Academic literature on the topic 'Axial internal force'
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Journal articles on the topic "Axial internal force"
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Wu, Er Jun, and Xing Chen. "Calculation on Plastic Internal Force of Reinforced Concrete Member under Axial Force." Applied Mechanics and Materials 578-579 (July 2014): 31–36. http://dx.doi.org/10.4028/www.scientific.net/amm.578-579.31.
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The design of reinforced concrete structure often used the elastic internal force as the design basis, but the nonlinear behavior of reinforced concrete structures brings about errors in calculation of statically indeterminate structure. By considering the nonlinear properties, the mechanical responses of reinforced concrete structure were investigated, on which an axial force loaded at their middle span section. In a series of analysis on internal force of the reinforced concrete member at all loading stages, through the deformation compatibility equation and the balance equation, the formulas for calculating elastic-plastic internal forces and strains were derived. Comparative examples are provided and the results show a large error between internal forces calculated by the structural mechanics method and those by the elastic-plastic method proposed in this paper, and the maximum error is about 8 times.
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Harada, Takashi, and Podi Liu. "Internal and External Forces Measurement of Planar 3-DOF Redundantly Actuated Parallel Mechanism by Axial Force Sensors." ISRN Robotics 2013 (October 9, 2013): 1–8. http://dx.doi.org/10.5402/2013/593606.
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This paper proposes a method for measuring the internal and external forces of a planar 3-DOF (degree of freedom) redundantly actuated parallel mechanism. The internal forces, force acts inside the endplate and mechanism constraint force, and the external forces, forces act on the endplate and thrusts by actuators, were measured simultaneously using the axial forces of the rods. Kinetostatic equations of the parallel mechanism were used to derive algorithms for measuring the internal and external forces. A link axis force sensor was developed using a strain gauge sensor. To verify the actual internal force of the endplate, a force sensor was also installed on the endplate. A real-time system for measuring the forces of the parallel mechanism was developed using RT-Linux. The external and internal forces were measured accurately.
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Wang, Jyhwen, and Rohit Agarwal. "Tube Bending Under Axial Force and Internal Pressure." Journal of Manufacturing Science and Engineering 128, no. 2 (June 15, 2005): 598–605. http://dx.doi.org/10.1115/1.2112987.
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Tube bending is a widely used manufacturing process in the aerospace, automotive, and various other industries. During tube bending, considerable in-plane distortion and thickness variation occurs. Additional loadings such as axial force and internal pressure can be used to achieve better shape control. Based on plasticity theories, analytical models are developed to predict cross-sectional distortion and thickness change of tubes under various loading conditions. The model predictions are in good agreement with finite element simulations and published experimental results. The models can be used to evaluate tooling and process design in tube bending.
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Zhang, Yu Ming, Guang Sheng Bian, and Tao Fan. "Calculation of Internal Force of Axial Tension Member due to Temperature Variation Accounting for Cracking." Advanced Materials Research 163-167 (December 2010): 1692–95. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.1692.
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Internal force of a concrete member duo to temperature variation is related to stiffness. A reduction of stiffness occurs and the magnitude of the internal forces drops from the values existing before cracking when cracking occurred due to temperature variation. Internal force of axial tension member due to temperature variation developed in a jagged style with cracking. Calculation method of internal force and stiffness reduction coefficient of axial tension member due to temperature variation was presented accounting for cracking. Given example shows stiffness reduction coefficient has a close relationship with number of cracks and steel ratio. Member with high steel ratio subjected to the same temperature variation has more cracks and smaller crack width.
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Zhang, Shi Min, Xing Ming Jia, Teng Kun Yuan, Wei Guo Liu, and Yin Jun. "Application of Axial Force Compensation for Steel Support System in Practical Project." Applied Mechanics and Materials 477-478 (December 2013): 503–8. http://dx.doi.org/10.4028/www.scientific.net/amm.477-478.503.
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The problem always exist in foundation pit engineering that the support axial force can not be regulated in the pit system in real time.According to setting the axial force compensation system,the problem would be solved perfectly and efficiently,realizing the fact control and adjust the support axial force and stability. The axial force compensation system which is constituted by jacks distributed in the pit has been confirmed the significant role to control foundation pit deformation and internal force monitoring combined with practical engineering
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Tsagkir Dereli, Tountzer, Nils Schmidt, Tim Furlan, Raphael Holtermann, Dirk Biermann, and Andreas Menzel. "Simulation Based Prediction of Compliance Induced Shape Deviations in Internal Traverse Grinding." Journal of Manufacturing and Materials Processing 5, no. 2 (June 8, 2021): 60. http://dx.doi.org/10.3390/jmmp5020060.
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Internal traverse grinding (ITG) using electroplated cBN tools in high-speed grinding conditions is a highly efficient manufacturing process for bore machining in a single axial stroke. However, process control is difficult. Due to the axial direction of feed, changes in process normal force and thus radial deflection of the tool and workpiece spindle system, lead to deviations in the workpiece contour along the length of the bore, especially at tool exit. Simulations including this effect could provide a tool to design processes which enhance shape accuracy of components. A geometrical physically-based simulation is herein developed to model the influence of system compliance on the resulting workpiece contour. Realistic tool topographies, obtained from measurements, are combined with an FE-calibrated surrogate model for process forces and with an empirical compliance model. In quasistatic experimental investigations, the spindle deflection is determined in relation to the acting normal forces by using piezoelectric force measuring elements and eddy current sensors. In grinding tests with in-process force measurement technology and followed by measurement of the resulting workpiece contours, the simulation system is validated. The process forces and the resulting characteristic shape deviations are predicted in good qualitative accordance with the experimental results.
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Maślak, Mariusz, and Małgorzata Snela. "The axial force influence on the flexibility of steel joints subject to bending under fully developed fire conditions." Budownictwo i Architektura 13, no. 3 (September 11, 2014): 251–58. http://dx.doi.org/10.35784/bud-arch.1827.
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The axial force qualitative influence as well as its quantitative evaluation on the behaviour of the flexible steel beam-to-beam and column-to-column knee joints subject to bending under fire conditions are assessed and discussed in detail. The proposed calculation algorithm is based on the generalization of classical component method. The essential effect of such axial force is not only the correction of internal forces applied to particular joint components, but also the significant modification of their strain conditions.
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Zhang, Shixiong, Xiang Li, Hongqiang Ma, and Haoju Wen. "Mechanical analysis of normal force interference on axial force measurement for internal sting balance." Aerospace Science and Technology 58 (November 2016): 351–57. http://dx.doi.org/10.1016/j.ast.2016.08.028.
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Zhang, Yao, Jun Dong, Guohua Li, and Xiufang Wang. "Calculation and Analysis of Truss Internal Force Based on Beam Element." Journal of Physics: Conference Series 2148, no. 1 (January 1, 2022): 012041. http://dx.doi.org/10.1088/1742-6596/2148/1/012041.
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Abstract For plane truss structure, starting from the analysis of ideal truss model, the influence of tangential deformation and angular deformation on the secondary internal force of the truss is fully considered through Python program. It is obtained through analysis that: in the ideal truss model, the Pδ second-order effect causes the member to produce tangential deformation and angular deformation, resulting in secondary internal forces. Numerical analysis shows that due to the influence of secondary internal force, the axial force error of ideal truss model can reach 19.731% and the secondary shear force is almost all the members of the truss, and the secondary moment only appears at the support. The research results have important reference value for the engineering design and high-precision internal force analysis of truss structures.
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Kim, Do-Young, Chang-Hoon Sim, Jae-Sang Park, Joon-Tae Yoo, Young-Ha Yoon, and Keejoo Lee. "Buckling Knockdown Factors of Composite Cylinders under Both Compression and Internal Pressure." Aerospace 8, no. 11 (November 15, 2021): 346. http://dx.doi.org/10.3390/aerospace8110346.
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The internal pressure of a thin-walled cylindrical structure under axial compression may improve the buckling stability by relieving loads and reducing initial imperfections. In this study, the effect of internal pressure on the buckling knockdown factor is investigated for axially compressed thin-walled composite cylinders with different shell thickness ratios and slenderness ratios. Various shell thickness ratios and slenderness ratios are considered when the buckling knockdown factor is derived for the thin-walled composite cylinders under both axial compression and internal pressure. Nonlinear post-buckling analyses are conducted using the nonlinear finite element analysis program, ABAQUS. The single perturbation load approach is used to represent the geometric initial imperfection of thin-walled composite cylinders. For cases with the axial compressive force only, the buckling knockdown factor decreases as the shell thickness ratio increases or as the slenderness ratio increases. When the internal pressure is considered simultaneously with the axial compressive force, the buckling knockdown factor decreases as the slenderness ratio increases but increases as the shell thickness ratio increases. The buckling knockdown factors considering the internal pressure and axial compressions are higher by 2.67% to 38.98% compared with the knockdown factors considering the axial compressive force only. The results show the significant effect of the internal pressure, particularly for thinner composite cylinders, and that the buckling knockdown factors may be enhanced for all the shell thickness ratios and slenderness ratios considered in this study when the internal pressure is applied to the cylinder.
Dissertations / Theses on the topic "Axial internal force"
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Bhattacharyya, A. Acosta Allan J. "Internal flows and force matrices in axial flow inducers /." Diss., Pasadena, Calif. : California Institute of Technology, 1994. http://resolver.caltech.edu/CaltechETD:etd-03012005-141633.
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Craveiro, Marina Vendl. "Upheaval buckling of pipelines triggered by the internal pressure resulting from the transportation of oil and gas: theoretical discussions and geometrically nonlinear analysis using Finite Element Method." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/3/3144/tde-06122017-082632/.
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The pipelines used to transport oil and gas from the wellheads to the distribution and refining sites can be subjected to high levels of pressure and temperature. Under such conditions, the pipelines tend to expand, but, if the expansion is inhibited, a significant compressive axial force can arise, leading to their buckling, which can occur in the horizontal or vertical plane. In this context, the objective of the present work is to analyze the upheaval buckling of pipelines, considering the internal pressure to which they are subjected during the transportation of oil and gas as its only triggering. Using the concept of effective axial force, it aims at discussing two different approaches for considering the internal pressure in buckling problems: distributed loads dependent on pipeline curvature and equivalent compressive axial forces with follower and non-follower characteristics. It also discusses the influence of using static or dynamic analysis for such approaches. Concerning the upheaval buckling itself, the work intends to analyze and compare the influence of the soil imperfection amplitudes to the influence of the friction between the pipeline and the ground in the critical loads and in the post-buckling configurations of the pipeline. Besides theoretical research, the objectives are achieved through the development of various numerical models, since geometrically-simple models, without the consideration of the interaction between the pipeline and the ground, until more complex models, with the use of contact models to detect the ground and its imperfections. The models are developed in Giraffe (Generic Interface Readily Accessible for Finite Elements) using geometrically-exact finite element models of beams, undergoing large displacements and finite rotations. Through the research, it is concluded that there is an equivalence between the application of the internal pressure as a distributed load dependent on pipeline curvature and the application of the internal pressure as a follower compressive axial force. Besides this, it is demonstrated that the type of the analysis (static or dynamic) depends on the nature of the physical system analyzed. With the aid of results presented in terms of internal pressure, classical results about the influence of the imperfection amplitudes and of the friction between the pipeline and the ground in buckling are confirmed. It is also showed that the imperfection amplitudes analyzed play a more important role in the post-buckling configurations of the pipeline than the friction.Os dutos utilizados para transportar petróleo e gás natural das reservas até os locais de distribuição e refino podem estar submetidos a elevados níveis de pressão e temperatura. Sob tais condições, os dutos tendem a se expandir, porém, se a expansão é inibida, uma força axial de compressão significativa pode surgir nos dutos, ocasionando a flambagem lateral ou vertical dos mesmos. Dentro desse contexto, o objetivo do presente trabalho é analisar a flambagem vertical de dutos, considerando a pressão interna à qual eles estão submetidos durante o transporte de petróleo e gás natural como o único parâmetro desencadeador da flambagem. Usando o conceito de força axial efetiva, o trabalho objetiva discutir duas abordagens diferentes para considerar a pressão interna nos problemas de flambagem: carregamentos distribuídos dependentes da curvatura do duto e forças axiais de compressão equivalentes à pressão com caráter seguidor e não seguidor. O trabalho também discute a influência de usar a análise estática ou dinâmica para analisar essas abordagens de carregamento. Com relação à flambagem vertical propriamente dita, o trabalho pretende analisar e comparar a influência das amplitudes das imperfeições presentes no solo com a influência do atrito entre o duto e o solo nas cargas críticas e nas configuração pós-críticas do duto. Além de pesquisa teórica, os objetivos são atingidos através do desenvolvimento de vários modelos numéricos, desde modelos geometricamente simples, sem a consideração da interação entre o duto e o solo, até modelos mais complexos, com o uso de modelos de contato para detectar o solo e suas imperfeições. Os modelos são desenvolvidos no Giraffe (Generic Interface Readily Accessible for Finite Elements) usando elementos finitos geometricamente exatos de viga, sujeitos a grandes deslocamentos e rotações finitas. Através da pesquisa, conclui-se que existe uma equivalência entre a aplicação da pressão interna como um carregamento distribuído dependente da curvatura do duto e a aplicação da pressão interna como uma força axial de compressão seguidora. Além disso, demonstra-se que o tipo de análise (estática e dinâmica) depende da natureza do sistema físico analisado. Com a ajuda de resultados apresentados em termos de pressão interna, os resultados clássicos sobre a influência das amplitudes das imperfeições e do atrito entre o duto e o solo são confirmados. Também é mostrado que as amplitudes das imperfeições analisadas desempenham uma maior influência nas configurações pós-críticas do duto do que o atrito.
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Лазарєв, Іван Вікторович, Иван Викторович Лазарев, and Ivan V. Lazariev. "Розробка та вдосконалення методів розрахунку міцності елементів конструкції силових трансформаторів." Thesis, Запорізький національний технічний університет, 2016. http://eir.zntu.edu.ua/handle/123456789/887.
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Лазарєв, І.В. Розробка та вдосконалення методів розрахунку міцності елементів конструкції силових трансформаторів [Текст]: дис. … канд. техн. наук: 01.02.04 /Лазарєв Іван Вікторович. – Запоріжжя, 2016. – 243 с.UK: Створено узагальнені методи визначення критичних напружень радіальної стійкості та розрахунку на міцність при дії радіальних і осьових сил гнучкого кругового кільця круглого та прямокутного з заокругленнями кутів перерізу, яке моделює провідники обмоток трансформаторів. Визначено осьові зусилля в деформівних елементах механічної системи, утвореної двома простими осциляторами з розташованими на одній осі безінерційними пружинами і твердими тілами, звязаними паралельними стержнями, на які діють відмінні у часі зосереджені аперіодичні осьові сили, що виникають при коротких замиканнях в обмотках різних фаз трансформатора, розміщених на одному стрижні магнітної системи. Розроблено методи визначення осьових зусиль в деформівних компонентах складної механічної системи, яку утворіють обмотки та конструкція їх пресування, при дії сил, що виникають у процесі виготовлення, транспортування, та експлуатації трансформаторів. EN: Transformer winding conductors were simulated by a flexible circular ring with round and rectangular (filleted and non-filleted) cross-section. For such a ring there were created generalised methods for determining critical stresses of radial stability and for strength analysis under the action of radial an axial forces. There were determined axial internal forces in deformable elements of the mechanical system comprising two simple oscillators with inertialess springs and rigid bodies located on the same axis and connected by parallel rods with the latter being loaded by concentrated aperiodic axial forces that change in time by distinct time functions and originate in windings of different transformer phases installed on the same magnetic system leg. There were developed methods for determining axial internal forces in deformable components of a complex mechanical system comprising windings and their clamping structure under the action of forces occurring in the process of transformer manufacture, shipment and in service. RU: Разработаны обобщенные методы определения критических напряжений радиальной устойчивости и расчета прочности при действии радиальных и осевых сил гибкого кругового кольца круглого и прямоугольного с закруглениями углов сечения, которое моделирует проводники обмоток трансформаторов. Определены осевые усилия в деформируемых элементах механической системы, образованной двумя простыми осцилляторами с расположенными на одной оси безынерционными пружинами и твердыми телами, связанными параллельными стержнями, на которые действуют сосредоточенные апериодические осевые силы, которые изменяются во времени по различающимся функциям, и возникают в обмотках разных фаз трансформатора, расположенных на одном стержне магнитной системы. Разработаны методы определения осевых усилий в деформируемых компонентах сложной механической системы, которую образуют обмотки и конструкция для их прессовки, при действии сил, которые возникают в процессе изготовления, транспортирования и эксплуатации трансформаторов.
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Stehno, Pavel. "Statické řešení novostavby administrativní budovy." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-226958.
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In this master’s thesis I study statical solution of new office building. The load – bearing elements are appraised according to ultimate limit state. Structural analysis contains of dimensioning ceiling plate with ribs, the most stressed support column and footing. There will be applied computer simulation to finding out values of internal forces. The solution is checked by simple method of replacement frames. The main purpose of this thesis consists of elaboration structural analysis, drawing up the technical report and creation design documents of load – bearing elements.
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Lipka, Miroslav. "Posouzení vlivu nového hlubinného základu na konstrukci primárního kolektorového tunelu." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225674.
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The purpose of the diploma thesis is assess the impact of piles on primary collector lining. Using a mathematical model has been calculated interaction between pile ond collector lining. The main task is to decide the length dependence of the pile deformations and internal forces that are the concrete lining of the collector.
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Bhattacharyya, Abhijit. "Internal flows and force matrices in axial flow inducers." Thesis, 1994. https://thesis.library.caltech.edu/818/1/Bhattacharyya_a_1994.pdf.
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Axial flow pump runners known as inducers are subject to complex internal flows and fluid-induced lateral and rotordynamic forces. The internal flows in inducers are three dimensional and are characterized by complicated secondary flows. The current research investigates the boundary layer flows on the blades, hub and housing of unshrouded and shrouded axial flow inducers using flow visualization techniques. Rotordynamic and lateral force data on unshrouded inducers were also obtained under varying conditions of flow and whirl.
Studies on the internal flows showed that the blade boundary layer flow had strong radial components at off-design conditions. The flow remains attached to the blade surface of unshrouded inducers at all flow coefficients tested. The origin of the upstream swirling backflow was found to be at the discharge plane of the inducer. In addition, flow reversal was observed at the suction side blade tip near the leading edge in a shrouded inducer. Re-entry of the hub boundary layer flow (a downstream backflow) into the blade passage area was observed at flow coefficients below design. For unshrouded inducers the radially outward flow near the blade tip mixed with the tip clearance leakage flow to form the upstream backflow. These observations provide a better understanding of the internal flows and the occurrence of upstream backflows in inducers.
The rotordynamic forces acting on an inducer due to an imposed whirl motion was also investigated. It was found that the rotordynamic force data at various whirl frequency ratios does not allow a normal quadratic fit; consequently the conventional inertial, stiffness and damping coefficients cannot be obtained and a definite whirl ratio describing the instability region does not result. Rotordynamic forces were found to be significantly dependent on the flow coefficient. At flow coefficients below design, these forces are characterized by multiple zero crossings at various whirl frequencies and large destabilizing peeks. Theoretical estimates of the tangential rotordynamic force on a non-whirling inducer using actuator disk theory were significantly different, both in magnitude and direction, from the experimentally measured forces.
The effect of upstream and downstream flow distortions on the rotordynamic and lateral forces on an inducer were studied. It was found that at flow coefficients below design, large lateral forces occurred in the presence of a downstream asymmetry. The reverse flows occurring downstream which consist of high energy fluid are the possible cause of these large forces. The imposition of a uniform downstream condition reduced these forces to near zero values. Results of inlet distortion experiments show that a strong inlet shear causes a significant increase in the lateral force. However, weak inlet shear flows and the flow asymmetry due to a 180° upstream bend did not cause a significant lateral force. It was found that flow distortions upstream or downstream did not cause any significant effect on the rotordynamic forces. Cavitation was found to have important consequences for fluid-induced rotordynamic forces. These forces become destabilizing for both forward and reverse whirl. The magnitudes of the destabilizing forces were found to increase with decreasing cavitation numbers.
Books on the topic "Axial internal force"
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Val'eho, Mal'donado, and Nikolay Chaynov. Calculation of kinematics and dynamics of inline piston engines. ru: INFRA-M Academic Publishing LLC., 2021. http://dx.doi.org/10.12737/1058850.
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The textbook discusses the kinematics and dynamics of inline piston internal combustion engines with axial and deaxial crank mechanism. The necessary material for calculating the forces and moments acting in the engine is given, the balancing of engines, the construction of vector diagrams of pressure on the crankshaft bearings are considered, examples of calculations are given.
Meets the requirements of the federal state educational standards of higher education of the latest generation.
For students of higher educational institutions studying in the field of training "Energy engineering".
Book chapters on the topic "Axial internal force"
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Fu, Wenqiang, Xinsha Fu, Yuting He, and Baijian Li. "Experimental Study on Mechanical Properties of a Medium Size Box-Type Corrugated Steel Bridge." In Advances in Transdisciplinary Engineering. IOS Press, 2021. http://dx.doi.org/10.3233/atde210161.
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Different from an arch bridge, the load-carrying capacity of a box structure mainly depends on the bending capacity of corrugated steel. This paper explores the mechanical properties of a corrugated steel box bridge. The mechanical properties of a 13 m span corrugated steel box bridge under static and dynamic loads were tested. Three static load conditions were tested, and four dynamic load conditions were tested, including 20 km/h, 40 km/h, 60 km/h, and 80 km/h. Through the analysis of section strain, vault displacement, dynamic strain, and internal force, the following conclusions can be drawn: (1) when the static load changes from the right arch foot and vault to the left arch foot, the strain value of each measuring point continues to increase, which may be caused by the accumulation of deformation due to the adjustment of the stress state of the soil and corrugated steel caused by loading; (2) the displacement change in the test is more sensitive than the strain change; (3) the vault strain reaches the maximum value at a specific speed of 60 km/h. This is related to the structural resonance caused by vehicle operation, and the natural frequency of the corrugated steel box bridge can be determined by a field vehicle dynamic load test; (4) the damping value of an embedded corrugated steel bridge is large, and the energy dissipation capacity is strong, which is very beneficial to structural earthquake resistance and to reducing the structural resonance under traffic load; (5) the dynamic increasing strain coefficient is less than 1, which means that the strain caused by a dynamic load is far less than that caused by a static load, and it reaches the maximum value at a certain speed (60km/h); (6) the maximum bending stress and maximum axial stress of the corrugated steel box bridge tested in this paper are basically the same, which indicates that the axial stress of the box structure cannot be ignored. However, the box structure design method proposed in the CHBDC code does not consider the axial stress, so it is necessary to further improve the box structure design method; (7) most of the axial force of a box corrugated steel bridge is tensile force. The pavement structure layer has an effect on the overall performance of the corrugated steel box bridge, which is similar to the decompression plate: it makes the overall stress (I ∼ V section) more uniform and the bending moment smaller.
Conference papers on the topic "Axial internal force"
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Liu, Podi, Tomoya Uchikoshi, Daichi Higashi, and Takashi Harada. "Internal and external force measurement of a redundant parallel mechanism by axial force sensors." In 2011 IEEE International Conference on Robotics and Biomimetics (ROBIO). IEEE, 2011. http://dx.doi.org/10.1109/robio.2011.6181765.
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Rahn, Christopher D., and C. D. Mote. "Axial Force Stabilization of Transverse Beam Vibration." In ASME 1993 Design Technical Conferences. American Society of Mechanical Engineers, 1993. http://dx.doi.org/10.1115/detc1993-0217.
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Abstract An axial force stabilizes the transverse vibration of a beam with translational and rotational boundary springs and arbitrary geometry. The nonlinearly coupled, longitudinal and transverse equations of motion of the beam with axial force control are derived and simplified using a quasistatic assumption. Lyapunov’s direct method and an invariance principle for distributed systems show that an axial damper can asymptotically and simultaneously stabilize all transverse vibration modes. Asymptotic stability is guaranteed if the eigenvalues are simple and nonzero and if there are no internal resonances between coupled modes.
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Shen, G., and W. R. Tyson. "Effect of Biaxial Stress on Crack Driving Force." In ASME 2006 Pressure Vessels and Piping/ICPVT-11 Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/pvp2006-icpvt-11-93849.
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A stress-strain equation of Ramberg-Osgood type is proposed to correlate the longitudinal stress with longitudinal strain of a thin plate when a constant stress is applied transversely. The same approach can be used to correlate the axial stress with axial strain for a thin-walled pipe in axial tension with internal pressure. The proposed stress-strain equation relating the longitudinal stress and strain closely approximates that of deformation theory. The effect of a secondary stress (hoop stress) on the J-integral for a circumferential crack in a pipe under axial load and internal pressure is evaluated by finite element analysis (FEA). The results show that the J-integral decreases with internal pressure at a given axial stress but increases with internal pressure at a given axial strain. It is concluded that while a secondary stress may be safely neglected in a stress-based format because it decreases the driving force at a given applied stress, it should not be neglected in a strain-based format because it significantly increases the driving force at a given applied strain.
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Fyrileiv, Olav, and Leif Collberg. "Influence of Pressure in Pipeline Design: Effective Axial Force." In ASME 2005 24th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2005. http://dx.doi.org/10.1115/omae2005-67502.
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This paper discusses use of the effective axial force concept in offshore pipeline design in general and in DNV codes in particular. The concept of effective axial force or effective tension has been known and used in the pipeline and riser industry for some decades. However, recently a discussion about this was initiated and doubt on how to treat the internal pressure raised. Hopefully this paper will contribute to explain the use of this concept and remove the doubts in the industry, if it exists at all. The concept of effective axial force allows calculation of the global behaviour without considering the effects of internal and/or external pressure in detail. In particular, global buckling, so-called Euler buckling, can be calculated as in air by applying the concept of effective axial force. The effective axial force is also used in the DNV-RP-F105 “Free spanning pipelines” to adjust the natural frequencies of free spans due to the change in geometrical stiffness caused by the axial force and pressure effects. A recent paper claimed, however, that the effect was the opposite of the one given in the DNV-RP-F105 and may cause confusion about what is the appropriate way of handling the pressure effects. It is generally accepted that global buckling of pipelines is governed by the effective axial force. However, in the DNV Pipeline Standard DNV-OS-F101, also the local buckling criterion is expressed by use of the effective axial force concept which easily could be misunderstood. Local buckling is, of course, governed by the local stresses, the true stresses, in the pipe steel wall. Thus, it seems unreasonable to include the effective axial force and not the true axial force as used in the former DNV Pipeline Standard DNV’96. The reason for this is explained in detail in this paper. This paper gives an introduction to the concept of effective axial force. Further it explains how this concept is applied in modern offshore pipeline design. Finally the background for using the effective axial force in some of the DNV pipeline codes is given.
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O’Rourke, Bryan, Donald Radford, and Rudolf Stanglmaier. "Tri-Axial Force Measurements on the Cylinder of a Motored SI Engine Operated on Lubricants of Differing Viscosity." In ASME 2009 Internal Combustion Engine Division Spring Technical Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/ices2009-76037.
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Friction is a determining factor in the efficiency and performance of internal combustion engines. Losses in the form of friction work typically account for 10–20% of an engine’s output. Improvements in the friction characteristics of the power cylinder assembly are essential for reducing total engine friction and improving the mechanical efficiency of internal combustion engines. This paper describes the development and implementation of a new concept of the ‘floating liner’ engine at Colorado State University that allows 0.5 crank angle degree resolved measurement of the forces on the cylinder along 3 axes — in the axial direction, the thrust direction, and along the wrist pin. Three different lubricants with differing properties were tested to observe the friction characteristics of each. Experimental results showed that the floating liner engine was able to resolve changes in friction characteristics coinciding with changes in lubricant viscosity and temperature. Axial force increases at TDC and BDC were observed as lubricant viscosity was decreased and larger amounts of mixed and boundary lubrication began to occur. For each test the axial friction force data was used to calculate total cycle friction work. The thrust and off-axis (wrist pin direction) forces are discussed under the same circumstances.
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Hao, Guangbo, Haiyang Li, and George Joseph. "Extended Nonlinear Analysis of Exactly-Constrained Compliant Compound Parallelogram Mechanisms." In ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/detc2015-46158.
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Extended nonlinear analysis of compliant compound parallelogram mechanisms is conducted in this paper. The analytical nonlinear model of a compound basic parallelogram mechanism (CBPM) is first derived incorporating the initial internal axial force. The stiffness equations of compound multi-beam parallelogram mechanisms (CMPMs) are then followed. The effect of initial internal axial forces on the primary motion is further analyzed, which can be employed to consider active displacement preloading control and thermal effects etc. It is shown that negative initial internal axial force will reduce the primary stiffness, and vice versa. The criteria for which the primary stiffness may be considered “constant” is defined and the initial internal axial force driven by temperature change is also formulated. The dynamic analysis of a CMPM using nonlinear finite element analysis (FEA) is finally carried out to show the modal frequency and the forced excitation response in the primary motion direction.
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Massa, Andre´ Luiz Lupinacci, Nelson Szilard Galgoul, Nestor Oscar Guevara Junior, Antonio Carlos Fernandes, Fa´bio Moreira Coelho, and Severino Fonseca da Silva Neto. "The Influence of Internal Pressure on Pipeline Natural Frequency." In ASME 2009 28th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/omae2009-79666.
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Galgoul et al. (2004) have written a previous paper in which they have pointed out the conservatism of the latest recommendations for pipeline freespan evaluations, associated to the way the axial force is considered in the determination of the pipeline natural frequency. First because it fails to consider the fact, that the axial force of a sagging pipe, subject to temperature expansion, is much smaller than that of a straight pipe. Second because the effective axial force caused by internal pressure should not be used to determine the pipeline natural frequency. Fyrileiv and Collberg (2005) also discussed this aspect. In order to back up their previous arguments the authors decided to perform some tests an axially restrained pipeline at both ends, which was pressurized in order to justify their claims that these pipelines are not only under tension (and not compression), but also that their natural frequencies increase instead of reducing, although they do bend out because of the pressure, reaching a point of instability. The authors understand the effective axial force concept and the enormous simplifications, which it brings to an otherwise cumbersome problem, but wish to emphasize that these advantages are not unlimited and that this is one of these restrictions. To back up the text results a finite element model has been produced, in which the internal pressure is taken into account as it actually is (and not as an axial force) to show that the pipe wall stresses can only be obtained correctly in this manner.
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Galgoul, Nelson Szilard, Andre´ Luiz Lupinacci Massa, and Cla´udia Albergaria Claro. "A Discussion on How Internal Pressure is Treated in Offshore Pipeline Design." In 2004 International Pipeline Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/ipc2004-0337.
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The design of rigid submarine pipelines has been the object of extensive research work over the last few years, where the most relevant issues include upheaval and lateral buckling problems. Both of these problems systematically associate temperature and pressure loads, where the treatment of the first is obvious, while the latter have always been a matter of discussion. In 1974 Palmer and Baldry [1] presented a theoretical-experimental contribution, in which they have set a pattern that has been followed ever since. Another similar and well known paper was published by Sparks in 1983 [7], who only present a physical interpretation of this same theory. Most of the present day industry codes define an effective axial force, according to which, fixed end pipelines will be under compression due to internal pressure. The starting point of the discussion presented in [1] was that internal pressure produces a lateral force, which is numerically equal to the pressure times internal cross-sectional area times the pipeline curvature: q=p.Ai.d2y/dx2(1) This equation is demonstrated further ahead in this paper. Palmer and Baldry then based their arguments on the traditional equation of the pinned column buckling problem, studied by Euler [2]: EId4y/dx4+Pd2y/dx2=0(2) for which the well known solution is: P=π2EI/L2(3) and on the associated problem studied by Timoshenko [3], which adds a distributed lateral load q to the same problem: EId4y/dx4+Pd2y/dx2=q(4) Replacing q with the lateral pressure given above, they were able to have their own problem fall back onto the Euler solution: EId4y/dx4+Pd2y/dx2=p.Ai.d2y/dx2P-pAi=π2EI/L2(5) After correcting for the Poisson effect they were able to determine the new critical axial force caused by the pressure. Unfortunately, however, the arguments set forth in [1] have been misunderstood. The fact that both axial force and lateral force multiply curvature does not make them forces of the same nature. Being able to add them has solved a mathematical equation, but still hasn’t converted the lateral force to axial. The authors wish to prove that [1] presents no more than a tool, which can be used in the analysis of global buckling problems of pipelines subject to both temperature and pressure. It will be shown, however, that this pressure will not produce an axial force, as now-a-days prescribed conservatively in many pipeline codes, which is even used for stress checking.
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Shen, G., S. M. Adeeb, R. I. Coote, D. J. Horsley, W. R. Tyson, J. A. Gianetto, and R. Bouchard. "Fatigue Crack Driving Force for Axial Surface Cracks in Pipes." In 2006 International Pipeline Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/ipc2006-10177.
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Fatigue life assessment procedures require knowledge of the fatigue crack driving force, such as stress intensity factor range (ΔK) and cyclic J-integral (ΔJ), for the flaw geometry detected during inspection. Because three-dimensional closed-form crack driving force solutions are not available for typical flaws in pipelines, it is common practice to obtain these solutions from finite element analysis (FEA) or to adopt a closed-form crack driving force solution for the equivalent flawed plate and include a correction factor to take account of the pipe bulging effect. In the present study, pipes and plates with an axial rectangular crack with filleted corners under fatigue loading are simulated by FEA. The initial results show that the stress intensity factor range (ΔK) for a thin-walled pipe with a shallow crack (a/t < 0.5) is given reasonably well by the bulging factors given in BS 7910 combined with the stress intensity factor equation given by Newman and Raju for a plate with a semi-elliptical crack. However, the stress intensity factor is significantly over-estimated for a long and deep crack using this procedure. Different parameters for elastic-plastic fatigue are calculated and are proposed to be correlated with the rate of crack growth for thin-walled pipes with an axial rectangular crack with filleted corners. It is intended to use the results presented here in combination with full scale experimental fatigue data to obtain pipeline fatigue crack growth formulations, to accurately predict the rate of crack growth within a pipeline due to fluctuating internal pressure.
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Zhu, Xian-Kui. "Limit Load Analysis of Cylindrical Vessels Under Internal Pressure and Axial Strain." In ASME 2011 Pressure Vessels and Piping Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/pvp2011-57175.
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Strain-based design is a newer technology used in safety design and integrity management of oil and gas pipelines. In a traditional stress-based design, the axial stress is relatively small compared to the hoop stress generated by internal pressure in a line pipe, and the limit state in the pipeline is usually load-controlled. In a strain-based design, however, axial strain can be large and the load-carrying capacity of pipelines could be reduced significantly below an allowed operating pressure, where the limit state is controlled by an axial strain. In this case, the limit load analysis is of great importance. The present paper confirms that the stress, strain and load-carrying capacity of a thin-walled cylindrical pressure vessel with an axial force are equivalent those of a long pressurized pipeline with an axial tensile strain. Elastic stresses and strains in a pressure vessel are then investigated, and the limit stress, limit strain and limit pressure are obtained in terms of the classical Tresca criterion, von Mises criteria, and a newly proposed average shear stress yield criterion. The results of limit load solutions are analyzed and validated using typical experimental data at plastic yield.