Статті в журналах: "Curved joints"

1

Zhang, Jing, Hong-wei Guo, and Zhan-ning Zhang. "Design of flexure revolute joint based on double compliant curved beam." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 13 (February 25, 2019): 4521–30. http://dx.doi.org/10.1177/0954406219833085.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

In view of the problems of low accuracy and large impact caused by flexure joints during the deployable process, design of an integrated flexure revolute joint for folding mechanisms is important. Using a double compliant curved beam as a flexible unit of a joint, the revolute joint is designed based on the method of compliance and stiffness ellipsoids. The geometrical constraints model of the curved beam is established to define the design range of the unit. The total error model, which is obtained by the analysis of single-parameter errors, is used to choose the size of the unit with the smallest error. The finite element models of the flexure joints are established to analyze the rotational stiffness, translational stiffness, and the maximum rotational angle of the joints. The rotational angle of one flexure revolute joint in one direction can reach 35.7°. The rotational angle of the series flexure revolute joint in one direction can achieve 51°. The experiments of single and series flexure joints are carried out to verify the correctness of the design and for the analysis of the flexure joint.

2

Makarov, Yurii, Roman Zaleskyi, and Mykola Mykhalichenko. "Influence of different factors on the value of the rail wear rate." Acta Technica Jaurinensis 17, no. 1 (February 28, 2024): 45–58. http://dx.doi.org/10.14513/actatechjaur.00735.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

The article deals with the study of the influence of train operating modes on the uphill and downhill sections with radii less than 450 m, as well as the influence of railway superstructure design in curved sections on the wear rate of rolling stock wheel flanges and rails. The aim of the research is to reduce the wear that occurs between the wheel flanges of the rolling stock and the rails. Rail joints have been found to be the main shock source in the dynamic interaction between the railway and the rolling stock. There is unstable motion within the transition curves and at the joints of the curved rail on the curved track sections. This is accompanied by abrupt lateral rail wear in the joint area between the trailing and facing rails in the direction of train movement. It has been found that reducing the weight of the trains leads to a reduction in intensive lateral rail wear on curved track sections and can reach the following percentages: in curves with a radius of up to 300 m: up to 33% uphill, up to 55% downhill; in curves with a radius of 300 m to 450 m: up to 32.9% uphill, up to 26.3% downhill; in curves with a radius of 450 m: up to 3.2% uphill, up to 17.6% downhill. On the uphill and downhill sections, reducing the height and adjusting to the speed limit in percentage gives a positive result from 4.7% to 53.59%.

3

Ayaz, Yaşar, and Çitil Şerif. "Mechanical behavior of butt curved adhesive joints subjected to bending." Materials Testing 63, no. 7 (July 1, 2021): 639–44. http://dx.doi.org/10.1515/mt-2020-0089.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Abstract Factors such as the surface geometry of a joint, the direction of the applied load, and the type of adhesive used have a great influence on the strength of a joint in adhesive bonding. In adhesively bonded joints (ABJ), it is possible to improve surface geometry by forming various geometric surfaces. ABJs are not very resistant to peeling stress, thus requiring that a bonding model be analyzed according to the direction of the applied load to prevent peeling stress. In this study, a butt curved joint was prepared from aluminum plates (A2024-T3) to improve the surface geometry of the joint. The mechanical behavior of the joints in three-dimensions and subjected to bending were investigated depending on an increase in the curvature radius. The adhesive DP810 was used for bonding. The finite element analysis was performed in ANSYS and cohesive zone modeling was used for a simulation of the damage growth in the adhesive layer. The results of bilinear and exponential models were found to be more appropriate to the experimental results. When the radius of curvature increases, the damage load carried decreases in the butt curved lap joints. It was seen that decreases in the curvature radius significantly decrease normal stress.

4

Çitil, Şerif. "Investigation of curved and scarf lap joints subjected to tensile loads using the cohesive zone model." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 17 (June 25, 2019): 6149–56. http://dx.doi.org/10.1177/0954406219858186.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

In this study, curved lap joints were designed, particularly for the cases in which configuration or aerodynamic design was essential. Furthermore, the effect of the surface area on their strength was investigated. Hence, curved joint types were prepared on aluminum plates (A2024-T3) that are commonly used for aviation, and an angled joint type was created by increasing the radius of curvature. The created joint types were then joined by a two-component acrylic structural adhesive (DP410). The joint models were designed in three dimensions, and a finite element analysis was performed. Cohesive zone models (bilinear, exponential, and separation-distance) based on energy principles were used in the finite element analysis to estimate the strength of the adhesively bonded joint. The mechanical properties of the materials used in the joint models were experimentally determined to obtain the numerical solutions, which were validated by further experiments. The obtained results demonstrated that there was an increase in the surface area on which the adhesive was applied as the radius of curvature of the scarf lap joints decreased; however, this had an adverse effect on the failure load that was carried.

5

Le, Jian, Hua Zhang, and Jin-wen Li. "Space curved fillet weld joints tracking by robots based on rotational arc sensors in gas metal arc welding." Industrial Robot: An International Journal 43, no. 6 (October 17, 2016): 636–46. http://dx.doi.org/10.1108/ir-04-2016-0120.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Purpose This study aims to improve the welding quality and efficiency, and an algorithm should be designed to realize tracking space-curved fillet weld joints. Design/methodology/approach Fillet weld joints tracking based on the two wheels and the horizontal slider coordinated movement has been studied. The method of pattern recognition is used to identify the height deviation, and the analysis of the accuracy corresponding to recognizing height deviations has been researched. The proportional control algorithm is used to control the vertical and horizontal sliders movement, so fillet weld joints tracking in the height direction has been achieved. Based on wheels and vertical and horizontal sliders coordinated movement, the algorithm of space-curved fillet weld joints tracking has been researched. Findings Some experiments have been done, and experimental results show that the welding robot can track space-curved fillet weld joints with high accuracy and good reliability. Research limitations/implications The welding robot can improve the welding quality and efficiency. Practical implications The welding robot can track fillet weld joints in ship panels, and it was shown that the welding robot could track space-curved fillet weld joints with high accuracy and good reliability. Social implications The welding robot has many industrial and social applications. Originality/value There are various forms of fillet weld joints in the industry, and the fillet weld is curved in the space. Experimental results show that the welding robot can track space-curved fillet weld joints with good stability and high precision.

6

Correia, J. M. C., R. D. S. G. Campilho, R. J. B. Rocha, Y. Liu, and L. D. C. Ramalho. "Parametric study of composite curved adhesive joints." International Journal of Advanced Manufacturing Technology 111, no. 9-10 (November 5, 2020): 2957–70. http://dx.doi.org/10.1007/s00170-020-06314-6.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Gantes, C. J., R. D. Logcher, J. J. Connor, and Y. Rosenfeld. "Geometric Design of Deploybale Structures with Discrete Joint Size." International Journal of Space Structures 8, no. 1-2 (April 1993): 107–17. http://dx.doi.org/10.1177/0266351193008001-211.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

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.

8

Faye, Khemendra. "Review Paper on Comparative Study of RCC Framed Building with and Without Expansion Joint at Different Location." International Journal for Research in Applied Science and Engineering Technology 10, no. 1 (January 31, 2022): 986–89. http://dx.doi.org/10.22214/ijraset.2022.39934.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Abstract: The pounding responses of the expansion joint in a curved ramp bridge under earthquake conditions. Long term effects of such seasonal temperature changes develop stresses and deformation in the building. Concrete creep and shrinkage increase the cracks widths and stresses. For elimination of this expansion joints are provided. The temperature expansion occurred most significantly during 20°C to 40°C and the optimised gradation could alleviate the arch expansion effectively, in the range of 20°C to 30°C. An expansion joint is a gap provided in the structure to allow expansion and contraction of the building due to temperature changes. It absorbs the heat-induced by expansion and contraction of various construction materials. Two theoretical models were used under eight types of seismic conditions. Results indicate that a curved ramp bridge without an abutment expansion joint is a favorable structure for seismic design. Keywords: Earthquake, pounding, Seismic Analysis, Expansion joints, Thermal stresses, Concrete Creep.

9

Edwards,, Brian T., Brian D. Jensen,, and Larry L. Howell. "A Pseudo-Rigid-Body Model for Initially-Curved Pinned-Pinned Segments Used in Compliant Mechanisms." Journal of Mechanical Design 123, no. 3 (June 1, 1999): 464–68. http://dx.doi.org/10.1115/1.1376396.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

The pseudo-rigid-body model concept allows compliant mechanisms to be analyzed using well-known rigid-body kinematics. This paper presents a pseudo-rigid-body model for initially curved pinned-pinned segments that undergo large, nonlinear deflections. The model approximates the segment as three rigid members joined by pin joints. Torsional springs placed at the joints model the segment’s stiffness. This model has been validated by fabricating several such segments from a variety of different materials. Testing of the force-deflection behavior of these segments verified the accuracy of the model.

10

Chaszar, Andre. "Digital detailing on the edge: joining of complex curved composite panels." PARC Pesquisa em Arquitetura e Construção 4, no. 2 (December 31, 2013): 30. http://dx.doi.org/10.20396/parc.v4i2.8634549.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

This paper concerns the detailing of panel edge joints within the context of an adaptive subdivision system for composite panelling of complex curved surfaces. A general overview of this context is provided, followed by more in-depth description of the challenges of joining the resulting panels as well as various alternatives for doing so. The alternatives are evaluated with respect to multi-criterion considerations including panel materials, machining capabilities, joint forces, joint orientation, appearance and weather-resistance among others, which are expected to vary from project to project – as well as possibly among locations within a project – and therefore affect the choice(s) of detailing.

11

YETKİN, Cüneyt, Şerif ÇİTİL, and Ali İhsan KAYA. "INVESTIGATION OF MECHANICAL PROPERTIES OF PIPES WITH BUTT CURVED LAP JOINTS SUBJECTED TO TORSION." Euroasia Journal of Mathematics, Engineering, Natural & Medical Sciences 8, no. 18 (November 25, 2021): 121–32. http://dx.doi.org/10.38065/euroasiaorg.797.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

In this study, the mechanical properties of steel pipe joints bonded with an acrylic adhesive under torsion were investigated by considering different overlap lengths and curvilinear radii. For this purpose, St-37 galvanized steel pipes with ØD = 21.3 mm outer and Ød = 15.9 mm inner diameters were modeled in three dimensions by creating 8, 10, 12 mm overlapping lengths in male and female form and 30, 40 and 50 mm curvilinear radii on the forehead regions. Numerical analyzes of the created models were performed in the ANSYS Workbench program, and samples with an overlap length of 10 mm were prepared on the CNC (Computer Numerical Control) bench to verify the numerical analysis. The prepared male and female specimens were joined using an acrylic-based DP810 structural adhesive resistant to humid environments, curable at room temperature, and validation experiments were carried out. After the study, obtained numerical and experimental data showed that pipe lap joints subjected to torsional moment with the same lap length but different curvilinear radius have been observed to vary significantly in the amount of load they carry. In addition, as the overlap length increased, the amount of load they carried increased. Also, in this study was compared by performing stress analyzes according to the overlap length and radii of curvature.

12

Nilsen, Morgan, Fredrik Sikström, Anna-Karin Christiansson, and Antonio Ancona. "Robust vision-based joint tracking for laser welding of curved closed-square-butt joints." International Journal of Advanced Manufacturing Technology 101, no. 5-8 (November 27, 2018): 1967–78. http://dx.doi.org/10.1007/s00170-018-3044-0.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Song, Q. Y., M. X. Zhang, W. J. Ding, H. M. Wu, and Y. C. Zhang. "Longitudinal structural behavior of shield tunnel with large diameter and small curvature." IOP Conference Series: Earth and Environmental Science 1333, no. 1 (May 1, 2024): 012056. http://dx.doi.org/10.1088/1755-1315/1333/1/012056.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Abstract The structural mechanism of a large-diameter curved tunnel is introduced in detail because no relevant calculation method is available. A longitudinal discontinuous contact model is established based on the newly built North Highway Tunnel in Shanghai, China. First, the load-spreading mechanism of circumferential joints was considered. Second, the distribution laws of the longitudinal internal force, settlement, and joint deformation of curved and straight tunnels under the same load were analyzed and compared. Finally, a model test is conducted to verify the effectiveness of the discontinuous contact model. The results indicated that with an increase in the radius of curvature, the maximum internal force and deformation decreased. The internal forces and deformations of straight and curved tunnels are quite different; therefore, the design method for a straight tunnel cannot be used in the design of curved tunnels. The overall and local deformations of the curved tunnel were affected by end displacement.

14

Huang, Min Yuan, and Zong Ren Zou. "Engineering Application of External Prestressing Curved Beam." Advanced Materials Research 639-640 (January 2013): 1249–52. http://dx.doi.org/10.4028/www.scientific.net/amr.639-640.1249.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Using the finite element software ANSYS to analyze dynamic characteristics of external prestressing structure, reasonable control parameter, as well as external prestressing reinforcement joints of security, the main research contents and results are as follows: Dynamic performance analysis is about variation law and internal feature. With the increase of external prestressing, on the contrary, the natural vibration frequency will reduce. However, external prestressing effects on the structural dynamic performance improvement that is not obvious in general. Based on sensitivity analysis, control parameter of external prestressing reinforcement curved beam must be analyzed and the reasonable value range of sensitive control parameter can be found. For the control parameter of external prestressing process, its reasonable control parameter’s range should be about 6% in the theoretical calculation. While simulating of anchoring system, local force on anchoring system must be analyzed finely and accurately. A comprehensive understanding should be mastered on variation law, which is about the internal forcing and stress response of special area. The setting of anchoring device shall be arranged at 1/3 place of original prestressing position. To ensure the safety, it should guarantee the mechanical continuity of anchor joints.

15

Huang, Na, Ming He, Haosheng Shi, Yuan Zhao, Man Lu, Xianbing Zou, Lei Yao, Huabei Jiang, and Lei Xi. "Curved-Array-Based Multispectral Photoacoustic Imaging of Human Finger Joints." IEEE Transactions on Biomedical Engineering 65, no. 7 (July 2018): 1452–59. http://dx.doi.org/10.1109/tbme.2017.2758905.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

16

Paulsen, William H. "Eigenfrequencies of curved Euler-Bernoulli beam structures with dissipative joints." Quarterly of Applied Mathematics 53, no. 2 (June 1, 1995): 259–71. http://dx.doi.org/10.1090/qam/1330652.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

17

Chen, Jihao, Yuxin Wang, and Qian Zhu. "Study on Load Transfer Mechanism of Local Curved Prestressed Hollow-Core Slab Bridge." Materials 16, no. 13 (June 29, 2023): 4708. http://dx.doi.org/10.3390/ma16134708.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

The assembled hollow-core slab bridge is the most widely used beam bridge in China. With the increasing traffic volume and traffic load in China, the joints of the hollow-core slab bridge are prone to damage. In this paper, a hollow-core slab bridge with locally curved prestressed tendons is proposed. Based on the static load test of a beam with joints taken from the cross section of a hollow-core slab bridge in practical engineering, a finite element nonlinear analysis is used to simulate the test, and the concrete and interface parameters under the correct analysis results are obtained. Finally, the parameters are applied to the three-beam and two-joint hollow-core slab bridge with a span of 10 m and a finite element analysis is carried out to explore the total failure process and performance improvement effect of the prestressed hollow-core slab bridge. The results show that the interface unit method can successfully simulate the new-to-old concrete interface where the joint is in contact with the precast beam segment. Compared with the static load test results, the analysis error of each finite element model is basically within 15%. Compared with the traditional hollow-core slab bridge, the cracking load, through-joint load, and ultimate load of the prestressed hollow-core slab bridge are increased by 50.0%, 91.7%, and 66.7%, respectively. Under the same load, the stress of the U-bar, the relative deflection of both sides of the joint, and the maximum width of the joint of the prestressed hollow-core slab bridge are lower than those of the traditional hollow-core slab bridge. When the ultimate load is reached, the longitudinal crack lengths of the traditional hollow-core slab bridge and the prestressed hollow-core slab bridge are 0.48 L and 0.4 L, respectively, and the damage degree of the prestressed hollow-core slab bridge is lower than that of the traditional hollow-core slab bridge.

18

Zheng, Xilong, Wei Li, Wei Li, Honglei Zhang, and Qiong Wang. "FINITE ELEMENT SIMULATION ANALYSIS OF CURVILINEAR CONTINUOUS BEAM BRIDGE JACKING AND TRANSLATION CONSTRUCTION." Stavební obzor - Civil Engineering Journal 33, no. 1 (April 30, 2024): 105–19. http://dx.doi.org/10.14311/cej.2024.01.0008.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

This paper investigates the issue of beam misalignment in curved continuous beam bridges. Taking the D0 to D6 spans of the Gongbin Road viaduct as the basis, the main influencing factors causing misalignment in curved beam bridges are analyzed and the causes of transverse and longitudinal misalignment in curved beam bridges are calculated and analyzed using Midas/Civil finite element simulation software. The results indicate that the main influencing factor causing misalignment in the operation of curved continuous beam bridges is the system temperature, with the displacement caused by it being larger than the cumulative displacement caused by self-weight, construction phase, gradient load, vehicle load, and bearing settlement. During operation, the failure of expansion joints changes the boundary conditions of the beam, preventing the bridge from freely expanding and contracting longitudinally under temperature load. As a result, the transverse displacement increases to 2-3 times the normal working state of the expansion joint, leading to beam misalignment.

19

Wang, Tian Li, Qing Ning Li, and Hai Jun Yin. "Research on the Seismic Response Characteristic of a Curved Ramp Bridge." Advanced Materials Research 243-249 (May 2011): 3889–92. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.3889.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

In order to analyze seismic response of the curved ramp bridge, this paper selected a single curved ramp bridge in a multilevel junction system as its research object. Considering the piers, beams, bearings and expansion joints simulation, it respectively built the calculating models for a curved ramp bridge and a corresponding linear one. Using nonlinear time history analysis, the paper contrasts seismic response of the curved ramp bridge with that of the linear one in several different seismic inputs. Finally the seismic response characteristic of a curved ramp bridge is put forward.

20

Tu, Jun, Xiao Wei Yi, Qi Ming Wu, and Rui Juan Jiang. "Analysis on the Lateral Creeping of a Curved Concrete Girder Bridge." Applied Mechanics and Materials 744-746 (March 2015): 845–49. http://dx.doi.org/10.4028/www.scientific.net/amm.744-746.845.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

In recent years, the lateral creeping happened from time to time to the curved concrete girder bridges when they are in service. This attracts much attention in the fields of the design, construction, maintenance of this kind of bridges since severe damage or collapse may happen to the whole structure when the lateral creeping displacement is large enough. In this paper, a comprehensive analysis is carried out on the lateral creeping of a curved two-span continuous concrete girder bridge which has been in service for 20 years to find out the possible reasons. A finite element model is appropriately developed for this example bridge using the commercial software Midas/Civil. Taking into account the dead loads, vehicle loads, thermal loads, etc., the safety and reliability of the original design of this bridge is proved first. And then the analysis is carried out for two possible reasons, bearing failure and expansion joints failure, respectively. The results show that the real reason of the bridge lateral creeping is that the expansion joints are stuck by the concrete blocks left when the expansion joints are replaced.

21

Mankame, Nilesh D., and G. K. Ananthasuresh. "A Novel Compliant Mechanism for Converting Reciprocating Translation Into Enclosing Curved Paths." Journal of Mechanical Design 126, no. 4 (July 1, 2004): 667–72. http://dx.doi.org/10.1115/1.1759360.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

This paper introduces a novel contact-aided compliant mechanism that uses intermittent contacts to convert a single translatory reciprocating input into two output curves, which intersect to enclose a two dimensional region. Contact interactions endow contact-aided compliant mechanisms with enhanced kinematic and kinetostatic capabilities. The mechanism described in this paper is designed to undergo large deformations repeatedly, without yielding by avoiding flexural joints and by using contacts to obtain the desired deformation. A single-material, joint-free and planar design makes the mechanism easy and economical to fabricate at the macro or micro scales. The design is validated experimentally by manufacturing and testing macro scale prototypes. Two potential applications that motivated this mechanism are also noted.

22

Li, Xinyue, Lei Lu, Cheng Fan, Fusheng Liang, Lining Sun, and Lei Zhang. "Ball-End Cutting Tool Posture Optimization for Robot Surface Milling Considering Different Joint Load." Applied Sciences 13, no. 9 (April 24, 2023): 5328. http://dx.doi.org/10.3390/app13095328.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Robots with openness and flexibility have attracted a large number of researchers to conduct in-depth studies in the field of surface machining. However, there is a redundant degree of freedom (DOF) in 6-DOF robot machining: when a ball end milling cutter is used to process curved parts, the tool point needs to strictly follow the planned milling trajectory, but the tool axis vector only needs to be within a certain range. During the machining process, the rotation of the tool around its axis is not constrained. Therefore, it is necessary to optimize the redundant DOF. Aiming at the redundant DOF of the tool axis vector in ball end milling for surface parts, a Redundancy Optimization strategy for Minimum Joint trajectory (ROMJ) is proposed. It takes the shortest trajectory of robot joints as the optimization objective, and the numerical optimization method is adopted to carry out the optimal design of tool axis vector trajectory in the milling process. Before optimization, to decrease the data volume, the number of track points is sampled and adjusted based on curve characterization errors. In the optimization process, considering the obvious difference in the load quality characteristics of the robot joints, a Redundancy Optimization strategy for Minimum Joint trajectory considering the different Load of joints (ROMJ-L) is proposed. The load difference coefficients of each joint are introduced into the optimization objective of the trajectory of robot joints. By using this method, the optimal design of each joint trajectory of the robot is realized. In order to verify the methods proposed in this paper, a comparison experiment is carried out. The results show that under the same tool point trajectory, the proposed methods can significantly reduce the robot joint trajectory, and the joint trajectory is influenced by the load difference of each joint. Finally, an Eflin-10 robot is used to process the butterfly trajectory tool path by the trajectory planned by the ROMJ-L method, and the results show that the method is practical.

23

Lin, Sheng, and Bi Cong Li. "A Wire-Driven Soft Manipulator Based on Flexible Curved Beam Joints." Procedia Computer Science 166 (2020): 434–37. http://dx.doi.org/10.1016/j.procs.2020.02.069.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Ferreira, P. A. R., R. D. S. G. Campilho, I. J. Sánchez-Arce, and D. C. Gonçalves. "Geometry effect on the static strength of curved composite bonded joints." Procedia Structural Integrity 51 (2023): 115–21. http://dx.doi.org/10.1016/j.prostr.2023.10.076.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

25

Mudrov, Andrej, Antanas Šapalas, Gintas Šaučiuvėnas, and Kęstutis Urbonas. "Moment Resisting Connection with Curved Endplates: Behaviour Study." Applied Sciences 11, no. 4 (February 8, 2021): 1520. http://dx.doi.org/10.3390/app11041520.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

This article provides a behaviour analysis of moment resisting joints with curved endplates. This is a new type of connection that can be used for joining steel beams to the circular hollow section (CHS) columns by means of bolts. Some researchers apply the Eurocode model without considering the differences in calculation schemes and assumptions, such as by using the general model of an equivalent T-stub in tension. Consequently, many of the existing behaviour studies are somewhat misleading, thus there is a need for further research. Apart from the absence of analytical methods that are devoted to predicting the initial stiffness and strength of the curved T-stub, other technical difficulties were encountered, such as gaps between the endplate and the column, as well as the initial pre-loading force of the bolts. In the previous studies, endplates were manufactured by rolling flat plates to the precise curvature which resulted in firm contact. In contrast, in this study, endplates were manufactured from a standard CHS tube, which led to significant initial gaps. Meanwhile, in terms of preloading force, it was found that it affected the moment resistance of the joint. This paper discusses problems associated with ongoing researches and presents experimental tests of the two connections. The obtained results were further used in the parametric finite element analysis (FEA) to determine the effect of the gaps and preloading force of the bolts on the moment resistance and initial rotational stiffness of the joint. The results indicate that the behaviour of curved plated connections is exceedingly complex and that the preloading force is the key factor, therefore, it should be controlled.

26

Holzer, S. M., C. H. Wu, and J. Tissaoui. "Finite Element Stability Analysis of a Glulam Dome." International Journal of Space Structures 7, no. 4 (December 1992): 353–61. http://dx.doi.org/10.1177/026635119200700411.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

The paper centres on stability investigations of a glued-laminated timber (glulam) dome under several snow load conditions. The dome consists of a triangulated network of curved glulam beams, a decking supported by curved purlins, and a steel tension ring. The dome is represented by two different models. The first model is a rigid-jointed space frame composed of curved beam elements. The second model consists of straight beam elements, with rigid or flexible joints, and a bracing to simulate the lateral support of the beams provided by the decking. Two finite element methods are presented and used in the analyses: A nonlinear method that computes the buckling load and a combined nonlinear/linear eigenvalue method that provides estimates of the buckling load. The results presented include buckling pressures, buckling modes, effects of joint stiffness and bracing on the stability of the dome, and the status of the material prior to buckling.

27

Bergamino, Chiara, Ruth Sanders, Ursula Fogarty, Antonella Puggioni, Clodagh Kearney, Florent David, and John David Stack. "Comparison of two ultrasound-guided injection techniques targeting the sacroiliac joint region in equine cadavers." Veterinary and Comparative Orthopaedics and Traumatology 29, no. 05 (September 2016): 386–93. http://dx.doi.org/10.3415/vcot-16-03-0041.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Summary Objectives: To compare the accuracy and distribution of injectate for cranial (CR) and caudomedial (CM) ultrasound-guided injections of equine sacroiliac joints. Methods: Both sacroiliac joints from 10 lumbo sacropelvic specimens were injected using cranial parasagittal (CR; curved 18 gauge, 25 cm spinal needles) and caudomedial (CM; straight 18 gauge, 15 cm spinal needles) ultrasound-guided approaches. Injectate consisted of 4 ml iodinated contrast and 2 ml methylene blue. Computed tomo-graphical (CT) scans were performed before and after injections. Time for needle guidance and repositioning attempts were recorded. The CT sequences were analysed for accuracy and distribution of contrast. Results: Intra-articular contrast was detected in sacroiliac joints following 15/40 injections. The CR and CM approaches deposited injectate ≤ 2 cm from sacroiliac joint margins following 17/20 and 20/20 injections, respectively. Median distance of closest contrast to the sacroiliac joint was 0.4 cm (interquartile range [IQR]: 1.5 cm) for CR approaches and 0.6 cm (IQR: 0.95 cm) for CM approaches. Cranial injections resulted in injectate contacting lumbosacral intertrans-verse joints 15/20 times. Caudomedial injections were perivascular 16/20 times. Limitations: Safety and efficacy could not be established. Clinical relevance: Cranial and CM ultra-sound-guided injections targeting sacroiliac joints were very accurate for periarticular injection, but accuracy was poor for intra- articular injection. Injectate was frequently found in contact with interosseous sacroiliac ligaments, as well as neurovascular and synovial structures in close vicinity of sacroiliac joints.

28

Bastian, A. J., T. A. Martin, J. G. Keating, and W. T. Thach. "Cerebellar ataxia: abnormal control of interaction torques across multiple joints." Journal of Neurophysiology 76, no. 1 (July 1, 1996): 492–509. http://dx.doi.org/10.1152/jn.1996.76.1.492.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

1. We studied seven subjects with cerebellar lesions and seven control subjects as they made reaching movements in the sagittal plane to a target directly in front of them. Reaches were made under three different conditions: 1) "slow-accurate," 2) "fast-accurate," and 3) "fast as possible." All subjects were videotaped moving in a sagittal plane with markers on the index finger, wrist, elbow, and shoulder. Marker positions were digitized and then used to calculate joint angles. For each of the shoulder, elbow and wrist joints, inverse dynamics equations based on a three-segment limb model were used to estimate the net torque (sum of components) and each of the component torques. The component torques consisted of the torque due to gravity, the dynamic interaction torques induced passively by the movement of the adjacent joint, and the torque produced by the muscles and passive tissue elements (sometimes called "residual" torque). 2. A kinematic analysis of the movement trajectory and the change in joint angles showed that the reaches of subjects with cerebellar lesions were abnormal compared with reaches of control subjects. In both the slow-accurate and fast-accurate conditions the cerebellar subjects made abnormally curved wrist paths; the curvature was greater in the slow-accurate condition. During the slow-accurate condition, cerebellar subjects showed target undershoot and tended to move one joint at a time (decomposition). During the fast-accurate reaches, the cerebellar subjects showed target overshoot. Additionally, in the fast-accurate condition, cerebellar subjects moved the joints at abnormal rates relative to one another, but the movements were less decomposed. Only three subjects were tested in the fast as possible condition; this condition was analyzed only to determine maximal reaching speeds of subjects with cerebellar lesions. Cerebellar subjects moved more slowly than controls in all three conditions. 3. A kinetic analysis of torques generated at each joint during the slow-accurate reaches and the fast-accurate reaches revealed that subjects with cerebellar lesions produced very different torque profiles compared with control subjects. In the slow-accurate condition, the cerebellar subjects produced abnormal elbow muscle torques that prevented the normal elbow extension early in the reach. In the fast-accurate condition, the cerebellar subjects produced inappropriate levels of shoulder muscle torque and also produced elbow muscle torques that did not very appropriately with the dynamic interaction torques that occurred at the elbow. Lack of appropriate muscle torque resulted in excessive contributions of the dynamic interaction torque during the fast-accurate reaches. 4. The inability to produce muscle torques that predict, accommodate, and compensate for the dynamic interaction torques appears to be an important cause of the classic kinematic deficits shown by cerebellar subjects during attempted reaching. These kinematic deficits include incoordination of the shoulder and the elbow joints, a curved trajectory, and overshoot. In the fast-accurate condition, cerebellar subjects often made inappropriate muscle torques relative to the dynamic interaction torques. Because of this, interaction torques often determined the pattern of incoordination of the elbow and shoulder that produced the curved trajectory and target overshoot. In the slow-accurate condition, we reason that the cerebellar subjects may use a decomposition strategy so as to simplify the movement and not have to control both joints simultaneously. From these results, we suggest that a major role of the cerebellum is in generating muscle torques at a joint that will predict the interaction torques being generated by other moving joints and compensate for them as they occur.

29

Liu, Ke, and Li Hui Wang. "Earthquake Damage of Curved Highway Bridges in 2008 Wenchuan Earthquake." Advanced Materials Research 838-841 (November 2013): 1571–76. http://dx.doi.org/10.4028/www.scientific.net/amr.838-841.1571.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

The curved bridges suffered severe damages or even collapsed during 2008 Wenchuan Earthquake. A field survey of seismic performance of RC curved bridges was examined. Damage patterns and the probable causes of RC curved bridges including Baihua bridge and ramp bridge of Huilan interchange are presented and analyzed in this paper. The main failure was pure shear failure or shear-flexural failure of the pier columns. Bearings and expansion joints damage were another common failure pattern. Lesson learned from the damage of RC curved bridges in this earthquake, the recommendations on the seismic design of RC curved bridges are presented involving ductility of bridge columns, design of curved bridges, design of bearings and devices preventing girders falling down. Suggestions for the future seismic design and retrofitting of RC curved bridges are also presented in moderate to severe earthquake area.

30

Mudrov, Andrej, Jean-Pierre Jaspart, Adrien Corman, and Antanas Šapalas. "ANALYTICAL MODEL FOR THE PREDICTION OF THE ELASTIC RESPONSE OF CURVED T-STUBS." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 27, no. 7 (October 6, 2021): 515–24. http://dx.doi.org/10.3846/jcem.2021.15206.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Composite steel-concrete columns utilise the advantages of both materials, by combining high strength and ductility of steel with the compressive strength of the concrete. But the wide adaptation of composite structures is limited, mainly because of the lack of cheap and easy to construct connections, as many of which require costly and timeconsuming on-site welding, when circular concrete filled steel tubes (CFST) are adopted. New connections, like those incorporating the use of blind bolts and curved end-plates, may represent a valuable alternative. Such joints can be adapted to circular CFST to eliminate on-site welding, but they require the creation of new curved T-stub components. This paper proposes an analytical model for the evaluation of bolt forces in the curved T-stubs within the elastic range. The model is then validated against experimental results of joints between circular CFST columns and steel beams, with both preloaded and snug tightened bolts. Analytical model shows good agreement with experimental data, but needs further development to take into account the prying forces.

31

Kuys, Blair, and Mozammel Mridha. "Aesthetic Preference of Timber Joints in Architectural Products." Sustainability 16, no. 1 (December 22, 2023): 154. http://dx.doi.org/10.3390/su16010154.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

This study investigates how Australian consumers’ aesthetic preferences for timber joints in architectural products are influenced by their sociodemographic characteristics and the visual appearance of the joints. Visual appearance in architecture and product design is a vital factor in consumer response and success of a product; however, designed items are often created without aesthetic research rigour to better understand user acceptance. We see this as an opportunity for greater penetration of aesthetics for designed products and, in this instance, contemporary architecture. We provide extensive literature defining aesthetics and outline the theoretical framework for experimental computer-generated visual stimuli. An online survey was conducted with 114 participants, who rated five timber joints on seven visual appearance attributes. The findings reveal that Joint 1 (angular) and Joint 5 (curved) were the most preferred joints. Employment status was the only sociodemographic factor that significantly affected the aesthetic preference. The findings of the study were used to inform design decisions for building a pagoda in a cemetery in Melbourne. The study contributes to the literature on aesthetics and design by providing empirical evidence on consumer preferences for architectural products. The study also suggests an opportunity to bridge aesthetics with sustainability, as timber is a sustainable material that can be designed to resonate with consumers’ aesthetic sensibilities while adhering to environmental principles.

32

Malgaca, Levent, and Şefika İpek Lök. "Measurement and modeling of a flexible manipulator for vibration control using five-segment S-curve motion." Transactions of the Institute of Measurement and Control 44, no. 8 (December 6, 2021): 1545–56. http://dx.doi.org/10.1177/01423312211059012.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

User designed manipulators are widely used in industry as a part of automation. The design of lighter robotic arms is required for less energy consumption. Joints, structural features, and payload affect the dynamic behavior of manipulators. Even if the arms have sufficient structural rigidity, joints, or payloads further increase their flexibility. These factors should be considered at the design stage. Flexibility causes vibrations, and these vibrations negatively affect robot repeatability and processing speed. Reducing the vibration levels of flexible manipulators is an attractive issue for engineers and researchers. Accurate estimation of the mathematical model of flexible manipulators increases the success of vibration control. In this paper, the modeling and experiments for vibration control of a single-axis flexible curved manipulator with payload are considered. The experimental system is introduced to collect vibration responses synchronously at the tip of the curved manipulator for angular velocity input. The mathematical model of the manipulator is estimated using the continuous-time system identification (CTSI) method with a black-box model based on the experimental input/output (I/O) signals. A five-segment S-curve motion input based on the modal parameters is designed to suppress residual vibrations. Vibration control is successfully performed for different deceleration times of the designed S-curve motion input. The results showed that the residual vibrations from experiments and predicted models matched well for different cases depending on payload, angular position, and motion time.

33

Marutyan, Alexander S. "Curved closed profiles and calculation of their optimal parameters." Structural Mechanics of Engineering Constructions and Buildings 15, no. 1 (December 15, 2019): 33–43. http://dx.doi.org/10.22363/1815-5235-2019-15-1-33-43.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Relevance. A new technical solution of bent-closed profiles relating to light steel thin-walled structures (LSTS), which have high technical and economic indicators and are widely used in industrial and civil construction, is presented. Aim of the research. The characteristics of thin-walled structures can be further enhanced by shaping the modification of profiles, combining in its composition the outlines of closed and open outlines. Methods. By means of developmental studies and optimization and design calculations for bent-closed profiles, their new technical solution was developed, the originality of which was confirmed by patent examination. Results. New curved closed profiles (CCP) consist of a tubular part of a single thickness and a double-thickness rib. For their manufacture without welded, bolted or riveted joints, the sheet blank is made along the entire length with serrated longitudinal edges, the teeth of which are arranged relative to each other in a staggered manner and mutually bent in grooves between themselves after the curved profile is closed along its edge. The bends of the gear fasteners increase the thickness of the collapse and provide an increase in the shear strength of the joints of thin-walled elements. With equal dimensions in height and width of the CCP, they are optimized by the criterion of uniform stability, which is the same from the plane and in the plane of the supporting structure. Additionally, a series of pentagonal, triangular and trapezoidal profiles are presen- ted, in which the lateral faces are inclined relative to the vertical at angles of 45 and 60 degrees.

34

Zheng, Yu, Chunfang Lu, Xiaomin Huang, Weibing Xu, Daxing Zhou, Jin Li, Jianxiang Li, Liqun Hou, Kuan Wang, and Yulong Sun. "Impact of Variable Parameters of Expansion Joints and Bearing Supports on the Vehicle-Induced Vibration of Curved Girder Bridges." Buildings 14, no. 1 (January 22, 2024): 293. http://dx.doi.org/10.3390/buildings14010293.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

To study how varying the parameters of expansion joints and bearing supports (E-B parameters) affects the dynamic response of a coupled vehicle–bridge system for curved girder bridges, a dynamic response analysis method for the coupled vehicle–joint (bearing)–bridge system, which takes into account centrifugal forces, was proposed and verified. Subsequently, taking a continuous curved box girder bridge as the prototype, the influence of the E-B parameters on the vehicle-induced dynamic response of the curved girder bridge was explored. The results showed that the dynamic amplification factor (DAF) of the middle beam of the expansion joint (DAF-EJ) and the main girder of the curved bridge (DAF-MG) were both significantly influenced by the E-B parameters. When there were height differences between the middle beam and side beam in the EJ, the DAF-EJ obviously varied, and the DAF-MG increased. When the EJ was damaged, the impact effect of the vehicle on the bearing support increased. The DAF-EJ and DAF-MG both increased with the decrease of the vertical support stiffness of the bearing support. The DAF-EJ was greatly affected by the single-support void at the near-slit end of the lane. The DAF-MGs at the beam end, the 1/4 point and 1/2 point of the first span, and the 1/2 point of the second span, were significantly affected by the single-support void near the measuring point. Compared with the single-support void, the DAF-EJ and DAF-MG more significantly increased under the double-support void. Variation in the height difference of the EJ had a more significant effect on the DAF-EJ and DAF-MG at the beam end, while a vertical stiffness reduction in the bearing support had a more significant effect on the DAF-MG.

35

Cammarata, Alessandro, Pietro Davide Maddio, Rosario Sinatra, and Nicola Pio Belfiore. "Direct Kinetostatic Analysis of a Gripper with Curved Flexures." Micromachines 13, no. 12 (December 8, 2022): 2172. http://dx.doi.org/10.3390/mi13122172.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Micro-electro-mechanical-systems (MEMS) extensively employed planar mechanisms with elastic curved beams. However, using a curved circular beam as a flexure hinge, in most cases, needs a more sophisticated kinetostatic model than the conventional planar flexures. An elastic curved beam generally allows its outer sections to experience full plane mobility with three degrees of freedom, making complex non-linear models necessary to predict their behavior. This paper describes the direct kinetostatic analysis of a planar gripper with an elastic curved beam is described and then solved by calculating the tangent stiffness matrix in closed form. Two simplified models and different contributions to derive their tangent stiffness matrices are considered. Then, the Newton–Raphson iterative method solves the non-linear direct kinetostatic problem. The technique, which appears particularly useful for real-time applications, is finally applied to a case study consisting of a four-bar linkage gripper with elastic curved beam joints that can be used in real-time grasping operations at the microscale.

36

BAHAT, D., A. RABINOVITCH, and V. FRID. "Correlation of plume morphologies on joint surfaces with their fracture mechanic implications." Geological Magazine 145, no. 5 (June 13, 2008): 733–44. http://dx.doi.org/10.1017/s0016756808004974.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

AbstractThe fractography and conditions of propagation of joints that cut Devonian siltstones in the Appalachian Plateau, New York, and Eocene chalks from the Beer Sheva Syncline, Israel, are investigated. The joints cutting the siltstones are marked by S-type and C-type plumes, and the joints cutting the Lower Eocene and Middle Eocene chalks are marked by coarse and delicate plumes, respectively. The four plume types propagated under sub-critical (slow propagation) conditions. On the semi-quantitative fracture velocity (v) versus the tensile stress intensity (KI) curves, the S and C plume types fall in the KI=0.073–0.79 MPa m1/2 and v=2×10−4–10−2 m/s and KI=0.073–0.79 MPa m1/2 and v=10−6–10−4 m/s ranges respectively. The coarse and delicate plumes fall in the KI=0.03–0.17 MPa m1/2 and v=10−6–4×10−5 m/s and KI=0.03–0.17 MPa m1/2 and v=10−4–5×10−3 m/s ranges, respectively. Generally, slow plumes are relatively short, show periodicity, and typically exhibit superposition of arrest marks. On the other hand, faster plumes are longer and continuous, occur particularly in thinner layers, and show no superposition of arrest marks. There is a clear distinction between two en échelon segmentation end-members in the joint fringe, the ‘discontinuous breakdown type’ and the ‘continuous breakdown type’. There are also ‘transitional’ variations between the end-members. Only curved ‘discontinuous breakdown type’ boundaries of en échelon fringes can be equated with mirror boundaries.

37

Wells, Zane G., Paul J. Barr, and Patrick H. James. "Performance of Posttensioned Curved-Strand Connections in Transverse Joints of Precast Deck Panels." Journal of Bridge Engineering 18, no. 10 (October 2013): 1062–73. http://dx.doi.org/10.1061/(asce)be.1943-5592.0000440.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

38

Madureira, Luisa R., and Francisco Q. Melo. "Hybrid formulation solution for stress analysis of curved pipes with welded bending joints." Engineering Fracture Mechanics 77, no. 15 (October 2010): 2992–99. http://dx.doi.org/10.1016/j.engfracmech.2010.04.009.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

39

Becker, Quentin, Seiichi Suzuki, Yingying Ren, Davide Pellis, Julian Panetta, and Mark Pauly. "C-Shells: Deployable Gridshells with Curved Beams." ACM Transactions on Graphics 42, no. 6 (December 5, 2023): 1–17. http://dx.doi.org/10.1145/3618366.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

We introduce a computational pipeline for simulating and designing C-shells , a new class of planar-to-spatial deployable linkage structures. A C-shell is composed of curved flexible beams connected at rotational joints that can be assembled in a stress-free planar configuration. When actuated, the elastic beams deform and the assembly deploys towards the target 3D shape. We propose two alternative computational design approaches for C-shells: (i) Forward exploration simulates the deployed shape from a planar beam layout provided by the user. Once a satisfactory overall shape is found, a subsequent design optimization adapts the beam geometry to reduce the elastic energy of the linkage while preserving the target shape. (ii) Inverse design is facilitated by a new geometric flattening method that takes a design surface as input and computes an initial layout of piecewise straight linkage beams. Our design optimization algorithm then calculates the smooth curved beams to best reproduce the target shape at minimal elastic energy. We find that C-shells offer a rich space for design and show several studies that highlight new shape topologies that cannot be achieved with existing deployable linkage structures.

40

Robeller, Christopher, Mina Konaković, Mira Dedijer, Mark Pauly, and Yves Weinand. "Double-layered timber plate shell." International Journal of Space Structures 32, no. 3-4 (June 2017): 160–75. http://dx.doi.org/10.1177/0266351117742853.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

This article presents a new lightweight construction system for doubly curved shells made from timber plates, inspired by the masonry vaults of Eladio Dieste. The system was developed for a specific case-study project, and general applications to other freeform surfaces are being discussed. The shells are built from two interconnected layers of structural wood veneer plates, using integral through-tenon joints for a fast, precise, and simple assembly. This allows for the construction of a series of differently shaped vaults without a costly mold or support structure. Instead, inclined joints cut with a 5-axis computer numerical controlled milling machine embed the correct location and angle between plates into the shape of the parts. This constrains the relative motions between joined parts to one assembly path. To take advantage of the benefits of such connectors, the constrained assembly paths must be considered in the fundamental design of the system, allowing for the insertion of each plate. This imposes additional constraints in the segmentation process of doubly curved shells. In order to meet the requirements and resolve the multi-constraint system, we use a global, nonlinear optimization approach. Developed as a close collaboration between architects, computer scientists and structural engineers, this article includes an experimental analysis of the influence of parametric modifications in the shape of connectors on their load-bearing performance.

41

Xu, Qiang, and Xing Jun Qi. "Analysis of Curved Girder Bridge Seismic Collision with Implicit Contact Algorithm." Applied Mechanics and Materials 94-96 (September 2011): 1898–901. http://dx.doi.org/10.4028/www.scientific.net/amm.94-96.1898.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Aiming at the collision phenomenon of the curved continuous girder bridge under the earthquake, the three-dimensional finite element model is established considering the collision element between the abutment and the end beam. Using the nonlinear time-integration method, the simulation analysis on the collision with implicit contact algorithm is used, and the collision law at expansion joints of curved gride bridge is studied. The results indicate that the shear forces and bending moments of piers with different heights are different. The collision force at the central part of the cross-section is small, and it gradually increases toward both sides of the cross-section with parabola. The outer collision force is bigger than the inner collision force, and the response of Elcentro ground motion is more obvious than that of Tianjin. The results may serve as a reference for seismic design of curved continuous bridges.

42

Massaquoi, Steve, and Mark Hallett. "Kinematics of Initiating a Two-Joint Arm Movement in Patients with Cerebellar Ataxia." Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques 23, no. 1 (February 1996): 3–14. http://dx.doi.org/10.1017/s0317167100039123.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

ABSTRACT:Objective:To characterize kinematically any systematic aberration in multi-joint movements in cerebellar ataxia.Methods:Nine patients with cerebellar degeneration and nine normal subjects, mobile only at the shoulder and elbow of the right arm, were required to produce left-to-right cross-body linear hand trajectories on the horizontal surface of a digitizing tablet. Nonlinearity indicated failure of precise coordination of the two joints. A wide range of hand speeds was studied. Data analysis was restricted primarily to the first 130 ms of movement.Results:As hand velocities increased, normal subjects and, especially, patients produced misdirected, curved paths. Normal subjects had significant curvature when peak speeds exceeded 100 cm/s and a trend toward significant bi-directional angular deviation at velocities greater than 300 cm/s. In patients, peak path curvature was significantly greater than normal at peak velocities of 50 to 200 cm/s. By 3.3 cm, their paths deviated significantly outward at all but the slowest speeds. Overall, patients’ maximal hand velocities and shoulder angular velocities, as well as maximal angular accelerations at both joints, were significantly lower than normal.Conclusions:The patients’ trajectory aberrations were attributed to a deficient rate of rotation at the shoulder relative to that at the elbow. Relative to task requirements, their rate of torque development was apparently deficient at both joints, but to a greater degree at the shoulder. Joint torque-rate impairment may contribute to the ataxia in both multi- and single-joint movements of patients with cerebellar disorders. A similar, but smaller impairment may produce milder nonlinearity in high-velocity movements of normal subjects.

43

Kang, H., H. Byun, and J. Lee. "PARAMETRIC MODELING TECHNOLOGY FOR APPLYING HBIM TO KOREAN TRADITIONAL WOODEN ARCHITECTURE." International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLVIII-M-2-2023 (June 24, 2023): 815–20. http://dx.doi.org/10.5194/isprs-archives-xlviii-m-2-2023-815-2023.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Abstract. The objective of this study was to apply parametric modeling for Korean traditional wooden buildings including joints using a script-based modeling engine. Korean traditional wooden buildings have complex structures composed of numerous members called joints and they are difficult to identify from the outside of the building. Therefore, creating the joints for the virtual modeling is essential to fully understand them. This study applied parametric modeling using the relationships and connectivity of each member.First, this study aims to create a single building by generating as many parametric models based on the drawings as possible, and supplementing with scanning models that are too complex to shape parametrically. Subsequently, various joint types were classified based on literature and drawings, and the parameters of each member were designed and systematized to apply to the building model. The methodology of this study can generate low-capacity models because it is based on scripts, unlike Scan-to-BIM and visualize various restoration plans for non-existing architectural heritage and virtual replication of traditional wooden buildings. Moreover, it can be utilized as a procedural modeling tool to create buildings at heritage by area including the surrounding landscape, and gradually applied to curved members using mechanical design.

44

Yamamoto, Yasuhiro, Kazuki Fujita, and Takeshi Iwamoto. "An Experimental Study on Axial Joint Strength Made of Fe-28Mn-6Si-5Cr Shape Memory Alloy at Various Deformation Speeds." Key Engineering Materials 725 (December 2016): 99–104. http://dx.doi.org/10.4028/www.scientific.net/kem.725.99.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Fe-SMA is attempted to be applied to large structural members such as pipe joints and vibration absorbers. However, if the pipe joint is used as pipelines and curved pipes in the underground, etc., it is considered that the applications require the long endurance for several loading conditions at various deformation rates. In the past, the axial strength of the pipe joint is estimated under a quasi-static tensile test at just single strain rate. However, it is hard to find papers which estimate the axial strength of the pipe joint as well as examining its rate sensitivity. In this study, at first, the pipe joint made of Fe-SMA is prepared. It is attempted to conduct a push-out test at various deformation rates and find the joint strength when a tightening function of the joint is lost. Here, the joint strength is defined by the strength when circumferential strain on the surface of joint starts decreasing. Additionally, rate sensitivity of axial strength defined is discussed.

45

Ropiak, L. Ya, V. S. Vytvytskyi, Т. О. Pryhorovska, and О. V. Pryhorovskyi. "Influence of spatial welding on the accuracy of working dimensions of drilling chisels of cutting-erasing type." Scientific Bulletin of Ivano-Frankivsk National Technical University of Oil and Gas, no. 1(50) (June 27, 2021): 42–52. http://dx.doi.org/10.31471/1993-9965-2021-1(50)-42-52.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

The article considers the problem of PDC drill bit quality provided during manufacturing. Schemes of welded joint making are theoretically substantiated based on theoretical research, computer modelling and experimental tests for L-shaped details like PDC drill bit blades. The recommendations to provide welded joints for L-shaped details are developed. Based on the elastic-plastic analysis, means to reduce thermal longitudinal and transverse internal deformations caused by a heat source moving along the weld are theoretically substantiated. Simulation models have been developed to assess the influence of welding thermal action and residual deformations on accuracy of drill bit external diameter for different schemes of welding. Based on the developed models, it is shown that the thermal welding deformations of spatial curved welds are significant, and relate mainly to the blades rather than the body (i.e. less massive parts); there are bends, turns and skews of the blades. Finite-element simulation of the bit body – welded blades stress-strain state was performed sequentially in the environment ANSYS (academic license) – Transient Thermal (determination of heat load) and Static Structural (determination of deformations and stresses). It is established that the smallest deformations of the blade are observed for the welding scheme, which envisages making the weld from the point of cylindrical and ellipse surface pairing. The results obtained by simulations were confirmed by experimental data and this made possible substitution for a rational scheme of drill bit body – blade based on the method of reverse deformation, to ensure the accuracy of the product as a whole. Recommendations for weld joint making for spatial curved welds of complex products with requirements to their accuracy allow increasing the accuracy of the technology by minimizing the thermal load and residual thermal deformation of the joints.

46

Al-Mukhtar, A. M., and Q. Doos. "The Spot Weldability of Carbon Steel Sheet." Advances in Materials Science and Engineering 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/146896.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

The specimens of thickness 0.8 mm carbon steel number 1.8902 in a strip form were welded. The strips of lap joints and curved peeljoints configurations have been welded. The welding parameters such as weld current and weld time have been investigated. The relation between the weld area and the joint strength properties has been presented. The obtained results were showing that the weld joint strength and the molten area (weld nugget volume) highly increase with the increasing of weld current. Therefore, the correlation between the maximum load (joint strength) and area has been given. The reliable weldability under the tensile and shearing loading was considered. Therefore, the new limits of weldability have been presented to consider these two types of loading. Moreover, the experimental results were compared with the empirical relations that consider the sheet thickness only.

47

Mishra, P. K., A. K. Pradhan, and M. K. Pandit. "Delamination propagation analyses of spar wingskin joints made with curved laminated FRP composite panels." Journal of Adhesion Science and Technology 30, no. 7 (December 20, 2015): 708–28. http://dx.doi.org/10.1080/01694243.2015.1121851.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

48

Jiang, Zhengwen, Shui Wan, Zhipeng Zhong, Shuqin Li, and Kongjian Shen. "Effect of curved delamination front on mode-I fracture toughness of adhesively bonded joints." Engineering Fracture Mechanics 138 (April 2015): 73–91. http://dx.doi.org/10.1016/j.engfracmech.2015.03.020.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

49

Chen, Yu, Ran Feng, and Chaoyang Wang. "Tests of steel and composite CHS X-joints with curved chord under axial compression." Engineering Structures 99 (September 2015): 423–38. http://dx.doi.org/10.1016/j.engstruct.2015.05.011.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

50

Koury, Kimberly, Jackson R. Staggers, Martim C. Pinto, Alexandre L. Godoy-Santos, Niall A. Smyth, Ashish B. Shah, and Cesar de Cesar Netto. "Radiographic Assessment of First Tarsometatarsal Joint Shape and Orientation." Foot & Ankle International 40, no. 12 (August 21, 2019): 1438–46. http://dx.doi.org/10.1177/1071100719868503.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Background: Hypermobility within the first tarsometatarsal (TMT) joint is a predisposing factor for hallux valgus. The purpose of this study was to assess whether the shape and angulation of the first TMT joint are affected by the positioning of the foot in radiographs. Methods: Ten adult above-knee fresh-frozen cadaveric specimens were placed into a radiolucent apparatus that allowed controlled angulation of each foot at 0, 5, 10, 15, and 20 degrees in dorsiflexion, plantarflexion, inversion, and eversion. For each specimen, the first TMT joint angle (1TMTJA), shape of the distal articular surface of the medial cuneiform (flat or curved), and image quality of the first TMT joint were measured. Results: The mean value for 1TMTJA was 22.9 degrees (95% confidence interval [CI] 21.9-24). Individual anatomical variations of the specimens as well as the different angulations due to foot positioning significantly influenced the 1TMTJA (both P < .001). Joints that were found to have a flat configuration showed significantly increased 1TMTJA on average when compared to the ones with curved articular surface, 25.9 (95% CI 24.4-27.4) and 20.8 degrees (95% CI 19.5-22.0) ( P < .001), respectively. Image quality for visualization of the first TMT joint was progressively better for increased angles of dorsiflexion and inversion. Conclusion: The shape and angulation of the first TMT joint on radiographic evaluation are affected by the positioning of the foot. Clinical Relevance: Clinical usefulness of these radiographic characteristics is limited and should not influence operative planning in patients with possible instability of the first TMT joint.

Статті в журналах з теми "Curved joints"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями