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1
Hao, Yan E., e Yong Qiang Lan. "Analysis on Setting Joints Technology in the Concrete Structure Buildings". Advanced Materials Research 971-973 (giugno 2014): 2052–56. http://dx.doi.org/10.4028/www.scientific.net/amr.971-973.2052.
Testo completoAbstract (sommario):
If reasonable joint is set in the design and construction of concrete structure buildings in advance as required, it can not only avoid or alleviate structural cracking and guarantee the quality of engineering construction, but also be good to improve the structural integrality and durability and lengthen service life of the buildings. This paper states the main types and functions of joints in the design and construction of reinforced concrete structure buildings. Then the major forms of setting joint technology are analyzed and discussed so as to provide references for relevant engineering technicians.
2
He, Chang, Faxing Ding e Yujie Yu. "Teaching Reform of Advanced Steel Structure Course Based on Accident Cases -Taking the Joint Design as an Example". Journal of Education and Development 6, n. 1 (30 marzo 2022): 22. http://dx.doi.org/10.20849/jed.v6i1.1072.
Testo completoAbstract (sommario):
The construction measures of steel structure joints have an important impact on the overall steel structure, the safety of the joint itself and the seismic performance of the structure. In the teaching of the node chapter of Advanced Steel Structure Course for undergraduates majoring in civil engineering, the focus is on teaching the calculation and design method of nodes, and only introductory explanations are given for the construction measures of nodes, and the students' learning effect is not satisfactory. This paper analyzed the current situation of teaching in the chapter of steel structure joints. Based on three engineering accident cases caused by improper joint construction measures, a case teaching idea was proposed. On this basis, the critical issues of teaching in this chapter and the application of cases were investigated. This paper aims to provide some reference opinions for the teaching reform of engineering-related courses, and to provide reference for the construction of practical teaching based on improving students' learning interest and autonomous learning ability.
3
Deineko, Andrei V., Valentina A. Kurochkina, Irina Yu Yakovleva e Aleksandr N. Starostin. "Design of reinforced concrete slabs subject to the construction joints". Vestnik MGSU, n. 9 (settembre 2019): 1106–20. http://dx.doi.org/10.22227/1997-0935.2019.9.1106-1120.
Testo completoAbstract (sommario):
Introduction. When erecting monolithic reinforced concrete floor slabs, a necessity of construction joints arises. The construction joints are the areas of structural weakening. The construction practice shows that the compliance with the correct technology of the construction joint arrangement is not a sufficient condition to ensure the strength balance of reinforced concrete floor slabs. As a result, the stress-deformation state calculated on the assumption of the concrete slab solidity deviates from the actual state. The relevance of the task is determined by the fact that the conformity of design and actual characteristics of the in-situ reinforced concrete structures as a whole depends on the correct calculations of construction joints.
Materials and methods. The problem of implementing the construction joints in the monolithic floor slabs was considered by way of example of a residential building under construction. In the course of construction, pre-construction land surveys were carried out at the areas of the construction joint arrangement. Calculations of reinforced concrete structures using finite element method (FEM) were also performed.
Results. As a result of the study, the actual deflections of the floor slabs were measured at the areas of the construction joints and FEM calculations were made on the same floor slabs, both those erected at once and those erected in stages subject to the construction joints. The difference between the calculated and actual deflections is conditioned upon the inaccurate conformity between the mathematical model and the real reinforced concrete structure, its erection and maintenance conditions. It should be noted that the deflection of horizontal reinforced concrete structures is only one of the stress-deformation state parameters that can be measured better than the others. It is shown that if the deflection of a real reinforced concrete structure does not correspond with the design estimation, the other stress-deformation state parameters will differ from the design estimation as well.
Conclusions. The influence of joints can be taken into account in the scope of FEM computer-aided calculations with the explicit reproduction of the structure erection by pouring concrete, using engineering approach to the consideration of nonlinearity on the basis of the introducing reduction coefficients to the reinforced concrete effective modulus of elasticity. Solid composition modeling of reinforced concrete provides the best possibilities on taking all sorts of nonlinearity manifestations into consideration.
4
Xiang, Wei Ming, Xian Chang Zheng, Kai Peng Shen e Ming Zhou. "Design of Broad-Columns Joint and Analysis of Stress for Top-down Construction Method of Underground Engineering". Advanced Materials Research 594-597 (novembre 2012): 1214–18. http://dx.doi.org/10.4028/www.scientific.net/amr.594-597.1214.
Testo completoAbstract (sommario):
According to the force problems caused by changing of structure forms of broad-column joints when using top-down construction method, this paper introduces the process of top-down construction method and design method of broad-column joint, using finite element software to analyze the stress of ring beam around broad-column joint, which is verified that adopting ring beam is safety and reliable, ring beam can transfer load and bear moment effectively, the strength of outsourcing column will be checked, finally it summarizes the characteristics of ring beam using top-down construction method.
5
Liu, Hongtao, Qiushi Yan e Xiuli Du. "Seismic performance comparison between precast beam joints and cast-in-place beam joints". Advances in Structural Engineering 20, n. 9 (20 ottobre 2016): 1299–314. http://dx.doi.org/10.1177/1369433216674952.
Testo completoAbstract (sommario):
Precast reinforced concrete structures are widely used due to many constructional advantages such as faster construction speed, lower construction cost, being environmentally friendly, higher strength, and so on. To study the seismic performance of precast reinforced concrete structures, tests on beam-to-column joints of precast reinforced concrete structures were conducted under low reversed cyclic loading. In total, four joint specimens were produced in this study, including two precast joints and two cast-in-place joints. In addition to the comparison between different types of joints, the axial compression ratio of column was adopted as the main variable in this study. Analysis was carried out on the basis of the observed joint failure mode and relationships derived from the test data such as hysteresis curves, skeleton curves, stiffness degradation curves, energy dissipation capacities, and sleeve joint strain curves. Despite the closeness of energy dissipation capacity between the precast joints and the cast-in-place joints, they had different failure modes. Precast joints feature a relatively concentrated crack distribution in which the limited number of cracks was distributed throughout the plastic zone of the beam. Cast-in-place joints feature more evenly distributed cracks in the plastic zone, especially at the later stage of the loading. The steel slippage of the precast concrete joints was found influenced by the axial compression ratio. Through this study, it is concluded that seismic resistance capacity of precast concrete joint needs to be considered in design and construction and the grouting sleeve splice could be kept away from the hinge zones when precast concrete structures were used in regions of high seismicity. The results in this study can provide a theoretical basis for seismic design of precast reinforced concrete structures, which in turn can promote the application of precast reinforced concrete structures.
6
Bródka, J. "Design Of Hollow Section Overlap Joints With Reinforcing Rib Plate. Joint Resistance". Archives of Civil Engineering 61, n. 1 (1 marzo 2015): 3–16. http://dx.doi.org/10.1515/ace-2015-0001.
Testo completoAbstract (sommario):
AbstractThese joints are used when the designer and contractor anticipate difficulties during the construction of overlap joints. They were not included in the PN EN 1993-1-8 in full scale. Resistance assessment of such joints is presented in accordance with standard rules. The results were compared with the experimental studies carried out at the “Mostostal” Centre; while the former research activities and the legitimacy of the proposed method of assessing the resistance of these joints was confirmed. This is an example of an overlap joint calculation.
7
Woytowich, Richard. "Riveted Hull Joint Design in RMS Titanic and Other Pre—World War I Ships". Marine Technology and SNAME News 40, n. 02 (1 aprile 2003): 82–92. http://dx.doi.org/10.5957/mt1.2003.40.2.82.
Testo completoAbstract (sommario):
Beginning with an overview of riveted joint construction, this paper shows that the efficiency of riveted joints in pre-World War I ships decreased as plate thickness increased. In the case of the RMS Titanic, some of the joints involved in the iceberg impact were only about 27% as strong as the plates they connected. A finite element model is used to show how such a joint would respond to the sort of out-of-plane load that the iceberg would have applied. For one possible load configuration, the joint failure is recreated. Finally, although Titanic and her sisters were not built to class, the design of the riveted joints is examined in the context of relevant Lloyd's Register of Shipping Rules.
8
Malhotra, S. K., e B. Thomas. "Effect of interface gap on load–slip characteristics of timber joints fabricated with multiple nails". Canadian Journal of Civil Engineering 12, n. 1 (1 marzo 1985): 104–13. http://dx.doi.org/10.1139/l85-011.
Testo completoAbstract (sommario):
An experimental program, exploratory in nature, has been carried out to investigate the effect of interface gap on the load–slip behaviour of joints fabricated with multiple nails. In total, 320 joint specimens have been tested. Modification factors are developed to account for the effects of number of nails and interface gap on the overall load-carrying capacity of joints with multiple nails. The current practice for the design of nailed joints is that a joint fastened together with multiple nails in a row, regardless of the interface characteristics of that joint, carries lateral load equal to the product of the lateral-load capacity of the corresponding joint with a single nail and the number of nails in a row of the joint. The findings of this investigation indicate this practice to be somewhat of an overestimation of the overall capacity of the joint. Key words: design, interface gap, interface friction, joint slip, loads (forces), modification factors, multiple fasteners, nailed joints, stiffness, structural engineering, tests, timber construction.
9
Lu, Wei, Qi Wang, Bei Jiang, Shuo Xu, Bohong Liu, Peng Zhang e Zhenhua Jiang. "Comparative study on bearing mechanism and design parameters of confined concrete arch joints in deep soft rock roadway". International Journal of Coal Science & Technology 6, n. 4 (12 novembre 2019): 493–504. http://dx.doi.org/10.1007/s40789-019-00272-5.
Testo completoAbstract (sommario):
Abstract Square confined concrete arch is increasingly used in deep soft rock roadway support because of its advantages of high strength and construction convenience. However, the design of confined concrete arch in underground engineering still remains in experience-based method and lacks quantitative analysis. As a connecting component between arch sections, the connection joints have an important influence on the internal force distribution and failure mechanism of support arch. Therefore, a reasonable design of arch joints is the premise of rational support design. Taking Liangjia Coal Mine, a typical deep soft rock mine in China, as research background, this paper fully compared the most widely used joint types of confined concrete arch as analytical objects: flange joints and casing joints. The main failure modes of these two kinds of joints under bending moment are defined. Laboratory and numerical tests are carried out to study the mechanical characteristics of joints. Based on the M–θ curve, the influence law of different design parameters is analyzed, and the design principles of joints are proposed. The research results could provide a theoretical basis for the design and application of confined concrete arch in related projects.
10
Støver, Eva Armstrong, Marte Haugen Sundsøy, Erlend Andenæs, Stig Geving e Tore Kvande. "Rain Intrusion through Horizontal Joints in Façade Panel Systems—Experimental Investigation". Buildings 12, n. 10 (21 settembre 2022): 1497. http://dx.doi.org/10.3390/buildings12101497.
Testo completoAbstract (sommario):
Façade panel systems with horizontal open joints are commonly used on larger buildings in Nordic countries. Excessive water intrusion through open joints may cause deterioration of the façade, a concern exacerbated by climate change. Previous studies have shown that current design recommendations for open-joint façade panel systems may not be optimal to prevent water intrusion. It is therefore of interest to investigate the watertightness of different design solutions for horizontal joints to inform recommendations for more durable façades. Large-scale measurements are conducted in a driving rain apparatus. Façade panel systems with different joint solutions are tested according to NS-EN 1027:2016. In total, 72 unique tests are conducted, investigating the impact of the four parameters: panel types, joint widths, joint profiles, and bevelled joint designs. All designs performed differently for the different types of panels, making it difficult to draw general conclusions. Smooth panels consistently exhibit higher water intrusion rates than rough panels, because runoff concentrates in streams on a smooth surface, causing localized, great intrusion in the horizontal joints. Modifications of the joints or the insertion of aluminium profiles may reduce or increase water intrusion. The most watertight among the investigated solutions involves an h-shaped profile. Bevelled joints improve overall watertightness but may direct more water towards the wind barrier. For open joints, a narrower joint width was found to decrease water intrusion to the wind barrier. In general, a barrier is needed to protect the joints against water intrusion. However, the effectiveness of protection measures depends on their design and mounting. Some protection measures led to greater water intrusion than no barrier at all.
11
Lanwer, Jan-Paul, Hendrik Weigel, Abtin Baghdadi, Martin Empelmann e Harald Kloft. "Jointing Principles in AMC—Part 1: Design and Preparation of Dry Joints". Applied Sciences 12, n. 9 (20 aprile 2022): 4138. http://dx.doi.org/10.3390/app12094138.
Testo completoAbstract (sommario):
The study described in this contribution contains a fundamental strategy to select geometries for dry joint profiles in 3D-printed concrete constructions. A database, here called the ‘joint catalogue’, contains a variety of joint types adapted from timber, steel, and bionic connections. Weighting factors and different criteria evaluate and score the various joint profiles (e.g., manufacturability, duration of manufacturing, and mechanical behaviour). Therefore, an algorithm sums up the scores leading to the preselection of better suitable profiles. The preselected joint profiles were afterwards analysed by the finite element method, determining the load capacity of the joint in a unit specimen. According to the joint catalogue, a smooth, triangular, truncated cone and arc joint profile appeared to be the optimal combination for dry joints in additive manufacturing of construction (AMC).
12
Valencia Clement, Gabriel F. "Joints in steel buildings". Ingeniería e Investigación 26, n. 1 (1 gennaio 2006): 71–83. http://dx.doi.org/10.15446/ing.investig.v26n1.14682.
Testo completoAbstract (sommario):
Masonry and steel components used in constructing buildings are in a constant state of motion. Volumetric changes are produced by temperature variation and deformation resulting from static or dynamic loading and in some materials, such as masonry, due to moisture content. This article addresses means of determining when expansion and seismic joints are required and how to proportion and design appropriate joints, specifically in steel buildings. It does not cover the study of expansion joints in concrete structures, in masonry construction or in non-structural (architectural) elements.
13
Kim, Haena, Byungkyu Moon, Xinyu Hu, Hosin (David) Lee, Gum-Sung Ryu, Kyung-Taek Koh, Changbin Joh, Byung-Suk Kim e Brian Keierleber. "Construction and Performance Monitoring of Innovative Ultra-High-Performance Concrete Bridge". Infrastructures 6, n. 9 (30 agosto 2021): 121. http://dx.doi.org/10.3390/infrastructures6090121.
Testo completoAbstract (sommario):
The application of Ultra-High-Performance Concrete (UHPC) materials in rehabilitating bridges and constructing primary bridge components is increasing rapidly across the world because of their superior strength and durability characteristics when compared to regular concretes. However, there have been few new bridges constructed using UHPC materials with regular formworks, ready-mix trucks, and construction equipment. This paper presents a comprehensive report encompassing the design, construction, and performance monitoring of a new bridge constructed in Iowa using a unique UHPC technology that includes steel fibers of two different lengths embedded in the concrete. By using optimized lengths of steel fibers, both the tensile strength and the toughness were increased. The UHPC material was produced with local cement and aggregates in the US using typical ready-mix concrete equipment. This paper discusses the experience gained from the design and construction process including mix design, batching, delivery of steel fibers to the ready-mix concrete batch unit, and post-tensioning of precast slabs at the jobsite. For four years after construction, the joints of the bridge decks were monitored using strain sensors mounted on both sides of the deck joints. The strain values were quite similar between the two sides of each joint, indicating a good load transfer between precast bridge girders. A bridge was successfully constructed using a unique UHPC technology incorporating two different lengths of steel fibers and utilizing local cement and aggregates and a ready-mix truck, and has been performing satisfactorily with a good load transfer across post-tensioned precast girder joints.
14
Wang, Feng En. "Frame Beam-Column Joints in the Design of the Concrete Strength Grade". Applied Mechanics and Materials 638-640 (settembre 2014): 120–22. http://dx.doi.org/10.4028/www.scientific.net/amm.638-640.120.
Testo completoAbstract (sommario):
the framework structure beam-column node stress is complex, the traditional design, the strength grade of concrete frame column than beam slab concrete strength grade is high, the construction to bring huge inconvenience. After some experiments and experience, the design of beam-column joints of concrete strength grade should improve, convenient construction, improve the quality of engineering.
15
Gaines, Ed, e John Banker. "Shipboard Aluminum/Steel Welded Transition Joints: Evaluations and Improvements". Journal of Ship Production 7, n. 03 (1 agosto 1991): 188–99. http://dx.doi.org/10.5957/jsp.1991.7.3.188.
Testo completoAbstract (sommario):
Aluminum-to-steel explosion-welded transition joints are used to attach aluminum superstructures to steel hulls. Transition joint bond separation sometimes occurs during ship construction. Ingalls Shipbuilding conducted a long-term study to determine causes and corrective action for these separations. Aluminum/steel transition joints are manufactured by the explosion-bonding process and tested in accordance with MIL-J-24445. Traditional transition joints consist of alloyed aluminum bonded to mild steel with an interlayer of low-alloy aluminum. The study reviews transition joint manufacture and quality testing required by material specification, adequacy of design guidelines and production practices, and cost-effective methods for corrective action. Modifications in product design and testing, installation design and shipyard production practices can improve reliability. The most important result of this study was development of material with improved properties. This paper relates the study procedure, findings and recommendations so that transition joint separations can be avoided on future installations. This information is useful for designers and transition joint users
16
Bu, Yonghong, Qi Yang, Yihong Wang e Dongfang Zhang. "Cyclic Testing of Bolt-Weld Joints Reinforced by Sleeves Connecting Circular CFST Columns to Steel Beams". Advances in Civil Engineering 2020 (28 gennaio 2020): 1–12. http://dx.doi.org/10.1155/2020/9674128.
Testo completoAbstract (sommario):
This study examined the design of joints reinforced by sleeves for connecting circular concrete-filled steel tube columns to steel beams. Six half-scale specimens, including four bolt-weld joints reinforced by sleeves and two bolt and stiffened end-plate joints, were designed and tested under cyclic loading to evaluate the seismic behavior of these joints. The joint construction and beam-column stiffness ratio were taken as the main parameters in the tests. The seismic behaviors, including the failure modes, hysteretic curves, ductility, strength and stiffness degradation, and energy dissipation, were investigated. The experimental results showed that no obvious bolt loosening, fracture, or widespread weld cracking appeared in the joints reinforced by sleeves. Furthermore, the joint strength and stiffness were markedly increased by the sleeves in the joint core area. Overall, most specimens exhibited full hysteresis loops and excellent ductilities, the equivalent viscous damping coefficients were 0.263∼0.532, and the ductility coefficients were 1.77∼3.42. The interstory drift ratios satisfied the requirements specified by technical regulations. The connections of these types exhibit favorable energy dissipations and can be effectively utilized for building construction in earthquake-prone areas. This research should contribute to the future engineering applications of concrete-filled steel tube to composite structure.
17
Shi, Xiaona, Xian Rong, Lin Nan, Lida Wang e Jianxin Zhang. "A New Steel-Joint Precast Concrete Frame Structure: The Design, Key Construction Techniques, and Building Energy Efficiency". Buildings 12, n. 11 (14 novembre 2022): 1974. http://dx.doi.org/10.3390/buildings12111974.
Testo completoAbstract (sommario):
Assembled methods play a critical role in the construction of precast concrete structures. However, conventional dry-connections-like sleeve grouting joints in precast concrete structures lagged at a low construction and management efficiency with poor quality control. In this study, a novel steel joint for precast reinforced concrete beam-column components is proposed to improve constructability. New joints transform the assembled method from reinforced concrete members into a steel structure by setting a pre-embedded steel connector at both ends of reinforced concrete beams and columns, showing outstanding economic, durability, and fire resistance capabilities. The construction process, construction efficiency, economy, and energy consumption were discussed based on the material, structure, and construction hybrid characteristics. Numerical simulation and structural health monitoring methods are used to monitor and evaluate the deformation and stress state of the proposed system in the whole construction process, so as to optimize the construction scheme and ensure safe and orderly construction. The results reveal that the FEA-simulated values of key building components during construction are in good agreement with the actual monitoring values, which verifies the feasibility of the FEM models and provides a guarantee for construction safety; the construction period of the proposed assemble system is reduced by approximately 56% and 40%, compared with the conventional reinforced concrete frame structure and cast-in-place joints in the precast concrete frame structure, respectively. Meanwhile, the energy consumption of buildings decreases by 20%. This research provides a theoretical basis for the design, calculation, and application of assembled precast structural systems.
18
Yin, Tulong, Zhan Wang, Kaixiang Zheng e Shengcan Lu. "A New Method for Design of the Semi-Rigid Steel Frame—The Integration of Joint Inverse Design and Structural Design". Buildings 12, n. 7 (1 luglio 2022): 938. http://dx.doi.org/10.3390/buildings12070938.
Testo completoAbstract (sommario):
In the past few decades, semi-rigid connections have been studied extensively; several major international steel structure design specifications have incorporated this component into their own systems. However, there is still no appropriate way to integrate the semi-rigid joint design into the structural design more efficiently. The forward design method of introducing joint characteristics into the frame by predetermining joint details requires considerable effort to trial massive amounts of variables, which is undoubtedly a nightmare for those structures composed of thousands of members and joints. In this paper, a feasible method for the reversed design of semi-rigid steel frames has been developed. Being similar to the traditional one, the structural design is still divided into member design and joint design. In the member design phase, a joint is abstracted as a performance parameter and its details are no longer concerned. Then, in the joint design phase, the joint details can be reconstructed subject to the joint required performance by using the optimization algorithm. Throughout the process, engineers simply tune the desired properties of the joins rather than their construction geometry, which results in clearer tuning direction and improved solution efficiency. In addition, determining how to choose a good, required connection stiffness as the starting design is discussed and recommendations are given. Finally, two examples are solved to verify the effectiveness of the proposed method.
19
Liu, Yin, Hong Wei Huang e Dong Mei Zhang. "Influence of Segment Design of Shield Tunnel on the Magnitude of Joint Opening". Advanced Materials Research 160-162 (novembre 2010): 698–703. http://dx.doi.org/10.4028/www.scientific.net/amr.160-162.698.
Testo completoAbstract (sommario):
It is obviously a simplification to consider the tunnel lining as uniformly permeable.In reality it is more likely that there are specific leaks assocoated with segmental lining joints. In the case of in situ concrete linings, construction joints can provide leakage paths, accounting for most of the water leakage. In this paper, based on the mechanical model of segment joint, the analytical expression of magnitude of joint opening was developed, in light of which, the occurrence of water leakage through the joint system can be judged. Taking the metro line No.1 in Shanghai as an example, effects of such parameters as joint flexural stiffness, bolt location, bolt stiffness, bolt prestress, etc. on the magninitude of the joint opening were analyzed respectively through the analytical solution. The results not only help us realize the influence mechanism of segment design on the magnitude of joint opening of the segmental linings, but also provide the guidance for waterproof design of the shield tunnel.
20
Piekarska, Wiesława, Alžbeta Sapietová, Zbigniew Saternus e Marcin Kubiak. "Computer analysis of thermal phenomena and deformation in lap joint welded by a laser beam". MATEC Web of Conferences 157 (2018): 02040. http://dx.doi.org/10.1051/matecconf/201815702040.
Testo completoAbstract (sommario):
Laser welding technology is applied to many types of welded joints. The determination of the influence of technological parameters on the properties of resulting joint is a significant problem for technologists. Numerical estimation of the shape of the weld and its deformation is important in the initial stage of construction design. The paper concerns computer analysis of thermal and mechanical phenomena in laser welded lap joint made of austenitic steel. Three dimensional discrete model of analyzed lap joint is created in Abaqus FEA engineering software. Numerical analysis takes into account temperature dependent thermomechanical properties of austenitic steel. The movable heat source power distribution is modelled using Gaussian distribution. Computational model takes into account the gap between the joined plates. Temperature distribution in analysed joints is presented on the basis of performed numerical simulations. The shape and size of the fusion zone as well as deformation of the joint are estimated.
21
Xingwen, Liu. "Research on Water Conservancy Project Construction and Operation Management based on Cost Management". E3S Web of Conferences 276 (2021): 01034. http://dx.doi.org/10.1051/e3sconf/202127601034.
Testo completoAbstract (sommario):
With the development and progress of the economy and society, the management level of my country’s construction projects has also been greatly improved, especially in the construction of water conservancy projects, and the cost management in the process has made significant progress; the water conservancy industry is in order to improve the market of enterprises. Competitiveness, to increase the market share of the company, it is necessary to improve the management level of the company in an all-round way, and maximize the economic benefits of the company.In order to improve the efficiency of cost management and operation management in the construction of water conservancy projects, this study conducts a theoretical analysis of the project cost management, taking the reinforcement treatment of the expansion joints of the culverts of the main canal project of the first phase of the water diversion water supply as a research case, and analyzes the expansion joints of the culverts of the project. This paper conducts a comprehensive investigation, proposes a repair plan using chemical bonding with external TPO waterstop and PTN petroleum asphalt polyurethane joint material, and makes a detailed investment estimate for project implementation. The results show that the bonding externally attached TPO waterstop and PTN petroleum asphalt polyurethane joint materials can meet the needs of this design for strengthening and strengthening the waterstop of the expansion joint of the culvert. The total static investment of construction engineering, mechanical and electrical equipment and installation engineering, construction temporary engineering, independent costs and basic reserve costs is 4,585,800 yuan, of which the total cost of underdrain expansion joint treatment is 3,594,600 yuan, which is in line with expectations, indicating that the water conservancy project of this design. The cost management plan is feasible.
22
Mousavian, Elham, e Claudia Casapulla. "Joint Layout Design: Finding the Strongest Connections within Segmental Masonry Arched Forms". Infrastructures 7, n. 1 (9 gennaio 2022): 9. http://dx.doi.org/10.3390/infrastructures7010009.
Testo completoAbstract (sommario):
Segmental arched forms composed of discrete units are among the most common construction systems, ranging from historic masonry vaults to contemporary precast concrete shells. Simple fabrication, transport, and assembly have particularly made these structural systems convenient choices to construct infrastructures such as bridges in challenging environmental conditions. The most important drawback of segmental vaults is basically the poor mechanical behaviour at the joints connecting their constituent segments. The influence of the joint shape and location on structural performances has been widely explored in the literature, including studies on different stereotomy, bond patterns, and interlocking joint shapes. To date, however, a few methods have been developed to design optimal joint layouts, but they are limited to extremely limited geometric parameters and material properties. To remedy this, this paper presents a novel method to design the strongest joint layout in 2D arched structures while allowing joints to take on a range of diverse shapes. To do so, a masonry arched form is represented as a layout of potential joints, and the optimization problems developed based on the two plastic methods of classic limit analysis and discontinuity layout optimization find the joint layout that corresponds to the maximum load-bearing capacity.
23
Madej, Jerzy, e Mateusz Śliwka. "Analysis of Interference-Fit Joints". Applied Sciences 11, n. 23 (2 dicembre 2021): 11428. http://dx.doi.org/10.3390/app112311428.
Testo completoAbstract (sommario):
Interference fit joints have been widely used in many engineering constructions, in particular in electric motors. It is of particular importance to calculate the load capacity of press-fit joints, especially in the overload ranges of construction to estimate the safety factor. The article presents a FEM numerical simulation of pressing the shaft into the hub, taking into account various types of fits. The results of numerical simulations presented in the article were positively verified with the MTS measuring device, which confirmed the correctness of the numerical model. So far, the load-bearing capacity of press-fit joints has been calculated from Lame’s formulas. The results of the load capacity of the joints obtained by the FEM simulation were compared with the results obtained from Lame’s formula. The comparison shows that when designing interference fit joints, attention should be paid to the fact that the press-in process, depending on the type of fit, may be elastic-plastic. Plastic deformations in the contact zone of the joint affect its load-bearing capacity. Therefore, the design of press-fit joints should not be based on Lame’s formulas, which do not take into account the range of plastic work of the material.
24
Sha, Mo, Ping Liu, Jierui Gao e Hua Ma. "Research status and application of prefabricated concrete frame joints". E3S Web of Conferences 260 (2021): 03025. http://dx.doi.org/10.1051/e3sconf/202126003025.
Testo completoAbstract (sommario):
Prefabricated concrete structure has the advantages of less energy consumption, easy quality control, fast construction speed, good construction site environment, and less contraction crack. As one of the important development directions of building structure at home and abroad, it is not only conducive to the development of China's construction industrialization and the improvement of production efficiency, but also greatly reduces the construction waste. The design of the connection between beam and column in the core plays an important role in the normal use and seismic performance improvement of the whole concrete structure. This paper reviews the research progress of prefabricated concrete frame joints both at home and abroad, introduce some applications of new connection, and analyses the merit and demerit of various connection methods and future development trend, in order to provide design reference for the engineering application of prefabricated concrete structure.
25
Beevers, D. J., e B. B. Seedhom. "Design of a Non-Constrained, Non-Cemented, Modular, Metacarpophalangeal Prosthesis". Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 209, n. 3 (settembre 1995): 185–95. http://dx.doi.org/10.1243/pime_proc_1995_209_342_02.
Testo completoAbstract (sommario):
A non-constrained, non-cemented, modular prosthesis for replacement of the metacarpophalangeal joints of the fingers has been developed. The prosthesis is of a surface design which is modular in construction and is implanted into the hones with a press fit. The prosthesis is designed to be implanted into patients with traumatic injuries, post-traumatic osteoarthritis and into patients with rheumatoid arthritis at an early stage in the disease where the muscles and ligaments that surround the joint are still functional and can provide joint stability.
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Gantes, C. J., R. D. Logcher, J. J. Connor e Y. Rosenfeld. "Geometric Design of Deploybale Structures with Discrete Joint Size". International Journal of Space Structures 8, n. 1-2 (aprile 1993): 107–17. http://dx.doi.org/10.1177/0266351193008001-211.
Testo completoAbstract (sommario):
This paper presents further developments in the geometric design of deployable structures that are self-standing and stress-free in both the deployed and collapsed configurations. The basic geometric design philosophy of these structures has been explained in previous publications. Furthermore, guidelines for the geometric design of polygonal and trapezoidal units for flat and curved structures have been proposed. The size of the joints has been assumed to be infinitesimally small. In reality however, the joints have certain discrete dimensions that have to be taken into account. This paper presents a more realistic geometric design procedure allowing for discrete joint sizes. First, a simple but accurate model is adopted for the joints that treats them as a grid of bars that are hinged to the members of the structure. Then, the geometric constraints and deployability conditions derived earlier are modified to account for joint size. Regular polygonal units for flat and curved structures, and trapezoidal units for flat structures are covered. An example of a medium size model is presented, where adjustments for the joint size had to be made during geometric design. Finally, the influence of joint size in the structural response during deployment is illustrated.
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Deng, Haiqian. "Research Status and Development Prospect of Steel Truss Bridge Joints". Highlights in Science, Engineering and Technology 10 (16 agosto 2022): 48–52. http://dx.doi.org/10.54097/hset.v10i.1225.
Testo completoAbstract (sommario):
In recent decades, with the increasing demand of long-span bridges and the continuous progress of construction technology, steel truss bridges have been more and more widely used. In general, the joint form of steel truss bridge can be divided into two types: splice joint and integral joint. The selections of the joint forms in steel truss bridges have gradually become the focus of the designers and researchers. Based on the engineering cases of steel truss bridges, this paper introduces the characteristics and advantages of the splice joint and the integral joint, respectively. The engineering performances of these two kinds of joints are compared under the same working condition. The corresponding conclusions on joint selection are obtained, and the prospect of joint design for steel truss bridges is proposed.
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Kirk, T. B., e G. W. Stachowiak. "Design and construction of a wear simulator for knee joints". Journal of Biomechanics 25, n. 7 (luglio 1992): 768. http://dx.doi.org/10.1016/0021-9290(92)90483-h.
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Karpilovsky, Viktor, Eduard Kriksunov, Anatoly Perelmuter e Vitalina Yurchenko. "ANALYSIS AND DESIGN OF STRUCTURAL STEEL JOINTS AND CONNECTION: SOFTWARE IMPLEMENTATION". International Journal for Computational Civil and Structural Engineering 17, n. 2 (24 giugno 2021): 58–66. http://dx.doi.org/10.22337/2587-9618-2021-17-2-57-65.
Testo completoAbstract (sommario):
The paper presents COMET software which enables to design steel structural joints widely used in civil and industrial engineering. Algorithm for designing each joint prototype has been presented as a set of operations implementing the rules for determining the interrelated values of the joint parameters. Each prototype is developed as an independent program that performs a full cycle of designing the joint and verification of the joint parameters according to the specified design codes.
Searching of unknown joint parameters has been transformed to a decision making problem based on analysis of the joint mathematical model. Automatic searching of unknown joint parameters has been implemented as a multiple targeted improvement of a certain initial joint design in order to satisfy load-carrying capacity constraints taking into account the structural and assortment-based constraints. Multiple improvement of current joint design is performed on the basis of sensitivity analysis relative to variation of governing joint parameters.
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Yang, Zhao, e Qing Hai Mei. "Analysis on the Holistic Resistant Behavior of Super High-Rise Structure Affected by the Concrete Strength of the Core of the Joints". Advanced Materials Research 631-632 (gennaio 2013): 747–53. http://dx.doi.org/10.4028/www.scientific.net/amr.631-632.747.
Testo completoAbstract (sommario):
There are some disadvantages in the concrete pouring method of column beam joints of super high-rise structures. If the concrete of joint core use the same strength grade with beams and plates, and pouring with them together, the construction process will be simplified and the construction quality will be easier to ensure. But the concrete strength of joint core is reduced, so whether the resistant behavior of the structure can be able to meet the design requirements is the key problem we focus on. The finite element model of a super high-rise structure was established by MIDAS software, the holistic resistant behavior of the structure was analyzed to study the effect of joint core concrete strength on the whole structure. The study provides the basis for further exploring a more reasonable pouring method of the concrete of the joints.
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Farbák, Matúš, Jozef Jošt, Richard Hlinka e Miroslav Rosmanit. "Numerical Analysis of the Load-Displacement Behaviour of Cast-in-Place Progressive Anchorage in Reinforced Concrete Members". Applied Sciences 11, n. 5 (6 marzo 2021): 2343. http://dx.doi.org/10.3390/app11052343.
Testo completoAbstract (sommario):
Modern construction requirements for building structures are currently focused on reducing the time required for construction, dealing with the lack of qualified human resources and ensuring comprehensive construction work quality. The problems mentioned above of today’s construction industry are significantly reduced by modern prefabrication and the efficient use of the most common building materials—steel and concrete. Critical components of such construction systems are their joints. Currently, there are many different types of joints of precast concrete structural elements. Integral parts of these joints are the various anchorages. For connecting load-bearing components, cast-in-place anchor systems are preferred to post-installed ones. The appropriate design of this small but crucial structural component is a complicated engineering issue in some cases. The finite element method (FEM) represents a practical opportunity to design and analyze anchorage systems in detail. A detailed numerical study based on an experimental program was performed to understand cast-in-place anchors’ real behavior and clarify some of the parameters of their design. This paper explains the creation of a numerical model, compares the FEM model with the performed experiments and presents the interesting results of the performed parametric study.
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Du, Shaoshuai, e Jinhua Tang. "State-of-the-Art Review on Failure Mechanism and Waterproofing Performance of Linings for Shield Tunnels". Advances in Civil Engineering 2022 (8 marzo 2022): 1–9. http://dx.doi.org/10.1155/2022/6104725.
Testo completoAbstract (sommario):
The introduction and development of shield tunnels have led to the innovation of precast segmental linings, which has significant advantages in improving the construction speed compared with in-situ cast concrete linings. However, damage of the linings and water leakage at the lining joints highlight defects in the design and construction of the linings. In this regard, it is necessary to investigate the failure mechanism of linings for shield tunnels and evaluate the waterproofing performance and repercussions of lining joints. The relevant research results published in recent years are reviewed in this paper, focusing on the failure mechanisms of linings and the waterproofing performance of lining joints. Progressive failure and instability of linings are introduced. Progressive failure has three stages: initial elastic stage, local damage stage, and overall failure stage. The performance-based design of joint waterproofing is described in seven steps. Further opportunities for the investigation of this topic are discussed.
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Li, Haifeng, BingQi Li e Bo Yang. "A Comparative Study of the Cracking Effect of Induced Joints of Various Spatial Formations". Mathematical Problems in Engineering 2019 (13 gennaio 2019): 1–9. http://dx.doi.org/10.1155/2019/7876503.
Testo completoAbstract (sommario):
The use of induced joints is a common cracking control measure used in the design of roller compacted concrete arch dams. Currently, in some projects in which radial twisted joints were used, during the construction period, some cracks appeared around the induced joints while the joints themselves failed to open. From the fracture mechanics point of view, this problem is related to the variations in the spatial formation of the induced joint planes. In this study, we formulated numerical examples involving square plate and cylindrical arch dam with joints of various planar spatial formations and used the virtual crack-closure technique and the Richard brittle fracture criterion to obtain the equivalent stress intensity factor of the joint plane, and we studied the joint plane stress intensity factor based on the variations in the joint plane formation angle. Based on the reciprocal of the normalized stress intensity factor, we obtained the equivalent strength correction coefficient for induced joints of varying plane angles, referred to in this study as the joint plane formation factor ψα, in order to reflect the influence of varying joint plane formations on the induced joint cracking. Our study results show that as the joint plane angle continuously increases, it is more difficult for the induced joints to open, which implies a gradual increase in the equivalent strength of the joint plane. Therefore, in the actual design of rolled concrete arch dams, the straight transverse joint layout should be used for induced joints. If the use of the radial twisted joint layout is necessary, the joint plane angle should not exceed 10°.
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Zhang, Dongfang, Junhai Zhao e Shuanhai He. "Cyclic Testing of Concrete-Filled Double-Skin Steel Tubular Column to Steel Beam Joint with RC Slab". Advances in Civil Engineering 2018 (26 luglio 2018): 1–15. http://dx.doi.org/10.1155/2018/7126393.
Testo completoAbstract (sommario):
The design of composite joints for connecting concrete-filled double-skin tubular (CFDST) columns to steel beams supporting reinforced concrete (RC) slabs is presented in this paper. Five half-scale specimens were designed, including four composite joints with RC slab and one bare steel beam joint, and were tested under a constant axially compressive force and lateral cyclic loading at the top end of the column to evaluate their seismic behavior. The main experimental parameters were the construction of the joint and the type of the column. The seismic behaviors, including the failure modes, hysteresis curves, ductility, strength and stiffness degradation, and energy dissipation, were investigated. The failure modes of the composite joints depended on the joint construction and on the stiffness ratio of beams to columns. Joints of stiffening type had significantly higher load-bearing and deformation capacities than joints of nonstiffening type. Compared with the bare steel beam joint, the bearing capacities of the composite joints with RC slabs were markedly increased. The composite action was remarkable under sagging moments, resulting in larger deformation on the bottom flanges of the beams. Overall, most specimens exhibited full hysteresis loops, and the equivalent viscous damping coefficients were 0.282∼0.311. The interstory drift ratios satisfied the requirements specified by technical regulations. Composite connections of this type exhibit excellent ductility and favorable energy dissipation and can be effectively utilized in superhigh-rise buildings erected in earthquake zones.
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Zhang, Wei, Zong Lin Wang e Fadhil Naser Ali. "Shear Stiffness of Segmental Joints in Cantilever Casting Concrete Bridges". Advanced Materials Research 250-253 (maggio 2011): 2460–67. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.2460.
Testo completoAbstract (sommario):
Joints between segments in cantilever casting concrete bridges require special attention in design and construction. These joints introduce discontinuity in the bridge; furthermore weaken the connection stiffness and strength of corresponding section, which may lead to excessive downwarping of bridge. Experiments were conducted to assess the shear stiffness of segmental joints section. The parameters studied included monolithic non-joints, joints roughened, joints roughened with shear-key. It was found that the shear stiffness of jointed section is largely lower than that of non-jointed section; however, the shear-key can effectively enhance the shear strength and especially shear stiffness of the joints section. Measures are proposed for shear-key design, and may provide a rational basis for the design of cantilever casting concrete bridges.
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Han, Ze Guang, Xin Fang Song e Rui Qin Hao. "The Assembled Structure Analysis of Energy Conservation and Material Saving Unit Sheet Aluminum Curtain Wall". Advanced Materials Research 243-249 (maggio 2011): 6165–68. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.6165.
Testo completoAbstract (sommario):
The joint between all plains in unit sheet aluminum curtain wall which is hanged on main body architecture is plugboard combination. The change of ambient temperature and wind load generates the change of expansion joints, which are the performance index of curtain wall required gas and water tightness, among curtain walls and suspension members. Thus obtained value of expansion joint among curtain walls is very important to guide the curtain wall’s installation. Here, an assemble structure model of curtain wall has firstly been established, the changing law of expansion joints among curtain walls has also been obtained under all kinds of work conditions based on previous model and the ANSYS software’s application. Some better suggestions have been also provided associating the construction technical specification. It can provide future protection for revised this technical specification, and accelerate the scientific normalization of the design in construction curtain wall.
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Grujicic, Mica, Jennifer Snipes, S. Ramaswami e Fadi Abu-Farha. "Process modeling, joint-property characterization and construction of joint connectors for mechanical fastening by self-piercing riveting". Multidiscipline Modeling in Materials and Structures 10, n. 4 (4 novembre 2014): 631–58. http://dx.doi.org/10.1108/mmms-04-2014-0024.
Testo completoAbstract (sommario):
Purpose – The purpose of this paper is to propose a computational approach in order to help establish the effect of various self-piercing rivet (SPR) process and material parameters on the quality and the mechanical performance of the resulting SPR joints. Design/methodology/approach – Toward that end, a sequence of three distinct computational analyses is developed. These analyses include: (a) finite-element modeling and simulations of the SPR process; (b) determination of the mechanical properties of the resulting SPR joints through the use of three-dimensional, continuum finite-element-based numerical simulations of various mechanical tests performed on the SPR joints; and (c) determination, parameterization and validation of the constitutive relations for the simplified SPR connectors, using the results obtained in (b) and the available experimental results. The availability of such connectors is mandatory in large-scale computational analyses of whole-vehicle crash or even in simulations of vehicle component manufacturing, e.g. car-body electro-coat paint-baking process. In such simulations, explicit three-dimensional representation of all SPR joints is associated with a prohibitive computational cost. Findings – It is found that the approach developed in the present work can be used, within an engineering optimization procedure, to adjust the SPR process and material parameters (design variables) in order to obtain a desired combination of the SPR-joint mechanical properties (objective function). Originality/value – To the authors’ knowledge, the present work is the first public-domain report of the comprehensive modeling and simulations including: self-piercing process; virtual mechanical testing of the SPR joints; and derivation of the constitutive relations for the SPR connector elements.
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Grujicic, Mica, JS Snipes e S. Ramaswami. "Process modeling, joint virtual testing and construction of joint connectors for mechanical fastening by flow-drilling screws". Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 231, n. 6 (30 marzo 2015): 1048–61. http://dx.doi.org/10.1177/0954405415577709.
Testo completoAbstract (sommario):
In this work, a computational approach is proposed in order to help establish the effect of various flow-drilling screw process and material parameters on the quality and the mechanical performance of the resulting flow-drilling screw joints. Toward that end, a sequence of three distinct computational analyses is developed. These analyses include the following: (a) finite element modeling and simulations of the flow-drilling screw process; (b) determination of the mechanical properties of the resulting flow-drilling screw joints through the use of three-dimensional, continuum finite element–based numerical simulations of various mechanical tests performed on the flow-drilling screw joints and (c) determination, parameterization and validation of the constitutive relations for the simplified flow-drilling screw connectors, using the results obtained in (b) and the available experimental results. The availability of such connectors is mandatory in large-scale computational analyses of whole-vehicle crash or even in simulations of vehicle component manufacturing, for example, car-body electro-coat paint-baking process. In such simulations, explicit three-dimensional representation of all flow-drilling screw joints is associated with a prohibitive computational cost. The approach developed in this work can be used, within an engineering-optimization procedure, to adjust the flow-drilling screw process and material parameters (design variables) in order to obtain a desired combination of the flow-drilling screw joint mechanical properties (objective function).
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Wang, Rong Xia, Hong Jiang Li e Ke Xi Jin. "Analysis on Shearing Deformation of Sectional Joints Affecting Deflection of Cantilever Constructed Box Girder". Advanced Materials Research 163-167 (dicembre 2010): 1364–68. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.1364.
Testo completoAbstract (sommario):
Over-deflection of beam in continuous rigid frame bridge has become an serious problem in recent years. The reason is complex. Some reseachers think that the bad quality of sectional joints in cantilever construction will cause additional shearing deformation and affect the beam deflection, this idea need to be further studied. In the paper, two three-dimensional models are built up based on a factual bridge, the simulation method of joints is studied, the influence of shearing deformation caused by sectional joints on beam deflection in construction is analysed. The study shows that shearing deformation of sectional joints has influence on deflection in cantilever construction, and it shouldn’t be ignored. This may be important to improve the loading property and renovate the design concept of this kind of bridge.
40
Ni, Hong Jie, Ying Sheng Ni e Jun Tian. "Contrastive Analysis on Hinge Joint Reinforcement Measures of Hollow Plate and Deduction Design Parameter". Applied Mechanics and Materials 578-579 (luglio 2014): 1379–95. http://dx.doi.org/10.4028/www.scientific.net/amm.578-579.1379.
Testo completoAbstract (sommario):
After describing the diseases on hinge joints of the hollow plate and analyzing causes, eight reinforcement measures are put forward and introduced herein accordingly. By means of solid finite element analyzing method, the article conducts a contrastive analysis on a variety of working conditions of those eight reinforcement measures, including the hinge joint stress and transverse distribution parameter. Three ideal methods are selected to conduct further analysis on the reinforcement effect of the hinge joint stress and it is concluded that there is risk in one way steel beam hinge joint reinforcement and two ideal methods are two-way steel beam reinforcement and adding transverse diaphragm in precast phase. From the perspective of fundamental solution to hinge joints, two-way reinforcement exerts more obvious effect on the bridges in service while adding transverse diaphragm is better for newly built bridges. Making it easy for design and construction, this paper offers constructive reference for engineering practice by deducting the vertical arrangement distance of the steel beam, presenting needs to be met by the shear resistance and flexural bearing capacity after verifying reasonable distance, discussing numbers and distance of transverse diaphragm and summarizing the strain of the external prestressed steel beam.
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Neto, João Batista da Silva, Gabriel Vieira Nunes, Arlene Maria Cunha Sarmanho, Daniel José Rocha Pereira, Messias Júnio Lopes Guerra e Vinícius Nicchio Alves. "Experimental and numerical assessment of CHS-RHS T-joints with chords subjected to axial tensile forces". Advances in Structural Engineering 24, n. 12 (8 aprile 2021): 2593–606. http://dx.doi.org/10.1177/13694332211003286.
Testo completoAbstract (sommario):
Hollow steel sections are widely used in the construction industry due to their mechanical properties. Joints used in these structures are the subject of research because of their singular and critical behavior. Joints containing chords with more slender cross-sections and axially loaded are still a challenge for design, especially in joints with circular hollow sections (CHS) in the braces and rectangular hollow sections (RHS) in the chords. In this context, this work aimed to study joints formed by a combination of CHS braces subjected to compression loads and RHS chords axially loaded with tension, welded as T-joints. Experimental tests, a numerical model using finite elements, and a parametric analysis were developed. A new equation for the chord stress function was proposed, including joints containing chords with semi-compact sections in tension. The joint resistance values obtained through the numerical models were compared with the equations from ISO 14346:2013 and with the proposed equation. It was observed that, for the numerical models with geometric properties inside the normative validity ranges of ISO 14346:2013, the mean rate of analytical by numerical joint resistance results was equal to 68%, using either the normative or the proposed equation. In the same way, for models outside the current validity ranges, either the proposed equation or the modified equation from ISO 14346:2013 could be used to design CHS-RHS T-joints with the geometric and material properties analyzed.
42
Yu, Haitao, Wenhao Xiao, Yong Yuan e Luc Taerwe. "Seismic mitigation for immersion joints: Design and validation". Tunnelling and Underground Space Technology 67 (agosto 2017): 39–51. http://dx.doi.org/10.1016/j.tust.2017.04.018.
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Jung, Erik, Victoria Ly, Christopher Cheney, Nicholas Cessna, Mai Linh Ngo, Dennis Castro e Mircea Teodorescu. "Design, Construction and Validation of a Proof of Concept Flexible–Rigid Mechanism Emulating Human Leg Behavior". Applied Sciences 11, n. 19 (8 ottobre 2021): 9351. http://dx.doi.org/10.3390/app11199351.
Testo completoAbstract (sommario):
In most robotics simulations, human joints (e.g., hips and knees) are assumed to be revolute joints with limited range rotations. However, this approach neglects the internal flexibility of the joint, which could present a significant drawback in some applications. We propose a tensegrity-inspired robotic manipulator that can replicate the kinematic behavior of the human leg. The design of the hip and knee resembles the musculoskeletal connections within the human body. Our implementation represents muscles, tendons and ligament connections as cables, and bones as rods. This particular design manipulates muscles to replicate a human-like gait, which demonstrates its potential for use as an anatomically correct assistive device (prosthetic, exoskeleton, etc.). Using the OpenSim 3.0 simulation environment, we estimated the kinematics and structural integrity of the proposed flexural joint design and determined the actuation strategies for our prototype. Kinematics for the prototype include the mechanical limitations and constraints derived from the simulations. We compared the simulation, physical prototype, and human leg behaviors for various ranges of motion and demonstrated the potential for using OpenSim 3.0 as a flexible–rigid modeling and simulation environment.
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Yun, Yanchun, Jiafei Jiang e Peng Chen. "Flexural Behavior of Lattice Girder Slabs with Different Connections: Experimental Study". Advances in Civil Engineering 2022 (27 dicembre 2022): 1–16. http://dx.doi.org/10.1155/2022/7722668.
Testo completoAbstract (sommario):
Lattice girder slab (LGS) is a precast composite slab that serves as an alternative to conventional concrete-in-place (CIP) slabs. The load-bearing capacity of joints for the LGSs is essential for large-span slabs with precast constructions, while limited connections could achieve both free-of-formwork construction and higher flexural bearing capacity. In order to enhance the flexural behavior of LGSs with free-of-formwork joints, the straight bar lapping connection away from the midspan, loop connection, and straight bar lapping connection within keyway for midspan joints were proposed in this study. Seven full-scale one-way LGSs with different transverse connections were tested under the four-point bending tests to investigate the joint behavior. The overall response and failure mode were observed during the test. The load versus midspan deflection, deflected shape, and characteristic load capacity were analyzed and discussed. The study showed that all the slabs’ deformability could reach as high as l/50 without load reduction. The LGS with the straight bar lapping connection in the midspan had the lowest flexural capacity (70% of the capacity for LGS without joints), while the flexural resistance of the slabs with other connections could be increased by 21.4% to 44.6% compared to LGSs with the traditional straight bar lapping connection in the midspan. The LGSs with the connections having keyways had the most significant improvement and could achieve high flexural capacity and 110% of deformability of the LGS without joints. The findings could enrich the connection types for LGSs for construction convenience and mechanical efficiency and further provide reference for the design of the two-way LGSs.
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Tankut, Ali Naci, e Nurgul Tankut. "Section modulus of corner joints in furniture frames as engineering design criteria for their efficient construction". Materials & Design 32, n. 4 (aprile 2011): 2391–95. http://dx.doi.org/10.1016/j.matdes.2010.10.027.
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Lee, Ilwha, Yeong-Tae Choi, Sungho Joh e Juhwan Um. "Deformation characteristics of discontinuous section of quick-hardening concrete tracks under full-scale test". Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 231, n. 3 (4 agosto 2016): 255–68. http://dx.doi.org/10.1177/0954409715626956.
Testo completoAbstract (sommario):
A quick-hardening concrete track has been developed to convert old ballast tracks into concrete tracks on operating lines. This method has been utilized to convert urban railways since 1997. With recent increases in train traffic and speed, maintaining track irregularities within design criteria has become essential to ensuring safety. On quick-hardening tracks, track irregularities are predominantly caused by irregular settlement around construction joints. These construction joints are inevitable in quick-hardening concrete; however, they create discontinuous sections that can affect the stable running of trains and structural durability. In this study, full-scale tests were performed with quasi-static and repeated loading on both continuous and discontinuous sections in which the earth pressure acting on the trackbed, accumulated settlement, and elastic displacement were measured. The results obtained indicate that construction joints are disadvantageous in terms of load transfer, settlement, and displacement. Additional field observations conducted on the Seoul Metro Line corroborated the results of the full-scale tests. The overall findings strongly suggest that construction joints on quick-hardening concrete tracks would need to be reinforced.
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Xiang, Ping, ZH Deng, YS Su, HP Wang e YF Wan. "Experimental investigation on joints between steel-reinforced concrete T-shaped column and reinforced concrete beam under bidirectional low-cyclic reversed loading". Advances in Structural Engineering 20, n. 3 (29 luglio 2016): 446–60. http://dx.doi.org/10.1177/1369433216653841.
Testo completoAbstract (sommario):
Steel-reinforced concrete T-shaped column-beam structure system has superiorities of both steel-reinforced structure and special-shaped column structure. This research focuses on steel-reinforced concrete T-shaped column-beam joint design and experimentally investigates seismic behaviors of the proposed joints. Pseudo-static tests are carried out on three steel-reinforced concrete T-shaped column-reinforced concrete beam joints and one reinforced concrete T-shaped column-reinforced concrete beam joint. The experiments were conducted under bidirectional low-cyclic reversed loading to simulate realistic loading conditions under earthquake. Hysteresis loops of all the specimens, including load–deflection, moment–rotation, and load–shear deformation loops, are plotted for the evaluation of seismic reaction. The working index, ductility coefficient, and equivalent viscous-damping coefficient are calculated for comparisons. Meanwhile, the ductility, capacity of energy dissipation, stiffness degradation, and the function of steel reinforcement in resisting shear force in the joint core area are intensively studied. Based on experimental results, this research analyzes shear-resistant capacity and the inner force transmission in these joints. It is found that the steel-reinforced concrete T-shaped column-reinforced concrete beam joint performs well under seismic conditions; moreover, shear-resistant capacity, ductility, and reliability are satisfactory. Conclusions derived from this research are useful for engineering practice.
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Liu, Zhengyu, Brent M. Phares, Weizhuo Shi e Behrouz Shafei. "Full-Scale Evaluation of an Innovative Joint Design between Adjacent Box Beams". Transportation Research Record: Journal of the Transportation Research Board 2674, n. 2 (30 gennaio 2020): 33–44. http://dx.doi.org/10.1177/0361198120902695.
Testo completoAbstract (sommario):
The longitudinal joints on adjacent precast, prestressed box beams used in bridge construction are vulnerable to cracking. These cracks provide a direct path for water and deleterious agents to enter the structural system, causing corrosion of the embedded steel bars and tendons. To avoid significant maintenance costs, safety concerns, or both, an innovative longitudinal joint between two adjacent box beams was designed in the current study. This joint is 6½ in. wide with roughened surfaces, filled with shrinkage compensating concrete and reinforced by steel bars. The joint was evaluated on a small-scale basis and satisfactory performance was obtained in resisting early-age cracks. In the current paper, the joint design is further evaluated through experiments on a 31 ft long specimen during the joint’s early age, and when it is subjected to multiple levels of cyclic loads. A finite element (FE) model that is capable of simulating the early-age concrete hardening was also developed and validated against the experimental data. The early-age, time-dependent stress development in the joint and at the interface of the joint and box beam was investigated using the FE model. Based on the results of laboratory tests and FE simulations, the innovative joint was found to remain crack free without the utilization of a shear key or transverse post-tensioning. The “compression-dominate” joint created by the expansive joint material and transverse reinforcing bars across the interface is expected to address the issues associated with early age, while ensuring the long-term durability and performance of box-beam bridges.
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Husain, Iqbal, e Dino Bagnariol. "Design and Performance of Jointless Bridges in Ontario: New Technical and Material Concepts". Transportation Research Record: Journal of the Transportation Research Board 1696, n. 1 (gennaio 2000): 109–21. http://dx.doi.org/10.3141/1696-14.
Testo completoAbstract (sommario):
It is well recognized that leaking expansion joints at the ends of bridge decks have led to the premature deterioration of bridge components. The elimination of these maintenance-prone joints not only yields immediate economic benefits but also improves the long-term durability of bridges. In Ontario, Canada, “jointless” bridges have been used for many years. Recently, the use of two main types of these bridges has increased dramatically. The first type is an “integral abutment” bridge that comprises an integral deck and abutment system supported on flexible piles. The approach slabs are also continuous with the deck slab. The flexible foundation allows the anticipated deck movements to take place at the end of the approach slab. Control joint details have been developed to allow movements at this location. The second type is a “semi-integral abutment” bridge that also allows expansion joints to be eliminated from the end of the bridge deck. The approach slabs are continuous with the deck slab, and the abutments are supported on rigid foundations (spread footings). The superstructure is not continuous with the abutments, and conventional bearings are used to allow horizontal movements between the deck and the abutments. A control joint is provided at the end of the approach slab that is detailed to slide in between the wing walls. Some of the design methods and construction details that are used in Ontario for integral and semi-integral abutment bridges are summarized. A review of the actual performance of existing bridges is also presented.
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Kou, Suxia, Xiuhua Zhang, Wancheng Li e Chunlei Song. "Dynamic Response Parameter Analysis of Steel Frame Joints under Blast Loading". Buildings 12, n. 4 (1 aprile 2022): 433. http://dx.doi.org/10.3390/buildings12040433.
Testo completoAbstract (sommario):
A finite element model of steel frame joints is established using finite element analysis software ANSYS/LS-DYNA. The ideal triangular impact load is used to numerically analyze the dynamic response of steel frame welded joints under blast loading, the main factors affecting this response, and the failure modes of three types of joints, so as to provide reference for the antiexplosive design of steel frame joints. The results show that steel frame joints vibrate violently in the explosive blast direction. Due to the strain rate effect, the strength of steel increases, the material enters the plastic strengthening stage, and there is a certain residual displacement. In addition, displacement and stress caused by blast action in the joint area are large, and the flange shear failure of the beam and column is prone to occur in the joint. Increasing the flange width of the beam and the column cannot improve the antiexplosive performance of the joints, while increasing their thickness can. Furthermore, bolted and welded joints have the highest stiffness and best antiexplosion performance, followed by welded joints, while the antiexplosion performance of bolted joints was the worst.