Simulative Analyses of Dynamic Buckling of Bellows

1996 ◽  
Vol 118 (2) ◽  
pp. 129-136 ◽  
Author(s):  
Y. Ooka ◽  
H. Ogawa ◽  
K. Ohno ◽  
K. Dozaki
Keyword(s):  
Finite Element ◽  
Computer Code ◽  
Dynamic Buckling ◽  
Test Results ◽  
Expansion Joints ◽  
Explicit Finite Element ◽  
Analytical Results ◽  
Deformation Modes

Simulative analyses of dynamic buckling have been performed for bellows of piping expansion joints for FBR plants using an explicit finite element computer code “RADIOSS.” Deformation modes were well simulated in comparison with the associated test results. As for critical buckling pressures, values obtained in the analyses were about 50 percent higher than test values, and further improvement is needed. This paper presents these analytical results and discussion. The associated test results are also reviewed for the arrangement of validation of the analyses.

Prediction of Tread Pattern Wear by an Explicit Finite Element Model3

2007 ◽  
Vol 35 (4) ◽  
pp. 276-299 ◽  
Author(s):  
J. C. Cho ◽  
B. C. Jung
Keyword(s):  
Finite Element ◽  
Wear Rate ◽  
Tangential Stress ◽  
Rate Equation ◽  
Constitutive Equations ◽  
Slip Velocity ◽  
Test Results ◽  
Explicit Finite Element ◽  
Driving Condition ◽  
Driving Conditions

Abstract Tread pattern wear is predicted by using an explicit finite element model (FEM) and compared with the indoor drum test results under a set of actual driving conditions. One pattern is used to determine the wear rate equation, which is composed of slip velocity and tangential stress under a single driving condition. Two other patterns with the same size (225/45ZR17) and profile are used to be simulated and compared with the indoor wear test results under the actual driving conditions. As a study on the rubber wear rate equation, trial wear rates are assumed by several constitutive equations and each trial wear rate is integrated along time to yield the total accumulated wear under a selected single cornering condition. The trial constitutive equations are defined by independently varying each exponent of slip velocity and tangential stress. The integrated results are compared with the indoor test results, and the best matching constitutive equation for wear is selected for the following wear simulation of two other patterns under actual driving conditions. Tens of thousands of driving conditions of a tire are categorized into a small number of simplified conditions by a suggested simplification procedure which considers the driving condition frequency and weighting function. Both of these simplified conditions and the original actual conditions are tested on the indoor drum test machines. The two results can be regarded to be in good agreement if the deviation that exists in the data is mainly due to the difference in the test velocity. Therefore, the simplification procedure is justified. By applying the selected wear rate equation and the simplified driving conditions to the explicit FEM simulation, the simulated wear results for the two patterns show good match with the actual indoor wear results.

Sensitivity Study of Boundary Conditions for a 9-Meter Drop of a Shielded Cask for Operational Handling of a Container of Liquid

2016 ◽  
Author(s):  
Michael C. Yaksh ◽  
Suresh Babu
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Boundary Conditions ◽  
Pressure Vessel ◽  
Element Model ◽  
Computer Code ◽  
Sensitivity Study ◽  
Confined Space ◽  
Explicit Finite Element ◽  
The Impact

A shielded cask is used to move welded containers whose contents are liquid. The requirement controlling the design of the shielded cask was the 9-meter drop. Since the orientation of the cask is arbitrary, it is required to assume an orientation which would result in the most damage to the cask. For such drops the target is usually considered to be an unyielding surface. The shielded cask of interest is not designed with components to mitigate the damage due to such drops. The shielded cask contains a thick shell of lead which is considered to move and deform during the 9-meter drop. Additionally, the container of liquid is not physically attached to the cask, and is free to move within the confined space during the event as well. Each component has its own unique stiffness and mass characteristics which could result in a different dynamic response. Since the dynamic response of each component is different, the most damage to a particular component may be sensitive to the boundary conditions. The unyielding surface would maximize the damage to the impact surface of the cask, but as a result, could mitigate the maximum loading applied to other components of the cask. Most actual targets are comprised of concrete. The evaluations are performed using an explicit finite element computer code. Consequently, it is necessary to monitor certain energies, such as the hourglass energy or a sliding energy indicating the behavior of the contact surface associated with the target. These parameters confirm the accurate behavior of the elements comprising the finite element model. Given that components can have a different response, the hourglass energy may also vary. Varying the boundary conditions will affect these types of parameters. In this paper, the authors present the results of a study of the effect of the boundary conditions on the shielded cask components response to the 9-meter drop. The primary orientation of interest is the end drop. The end drop maximizes the axial loading to the container. It is this orientation which could result in the most compression of the lead shield leading to increased radiation exposure. The container is considered as a pressure vessel and its integrity would be evaluated using the plastic strain based criteria contained in Section III, Division 3. The shielded cask, however, is not a pressure vessel and was evaluated using Section VIII, Division 2, Part 5. Both evaluations used the plastic strains and triaxiality factors determined from the drop evaluations.

Tire Cornering Simulation Using an Explicit Finite Element Analysis Code

1998 ◽  
Vol 26 (2) ◽  
pp. 109-119 ◽  
Author(s):  
M. Koishi ◽  
K. Kabe ◽  
M. Shiratori
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Test System ◽  
Experimental Results ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Explicit Finite Element Analysis ◽  
Element Method

Abstract The finite element method has been used widely in tire engineering. Most tire simulations using the finite element method are static analyses, because tires are very complex nonlinear structures. Recently, transient phenomena have been studied with explicit finite element analysis codes. In this paper, the authors demonstrate the feasibility of tire cornering simulation using an explicit finite element code, PAM-SHOCK. First, we propose the cornering simulation using the explicit finite element analysis code. To demonstrate the efficiency of the proposed simulation, computed cornering forces for a 175SR14 tire are compared with experimental results from an MTS Flat-Trac Tire Test System. The computed cornering forces agree well with experimental results. After that, parametric studies are conducted by using the proposed simulation.

scholarly journals Theoretical analysis and experimental research on multi-layer elastic damping track structure

2021 ◽  
Vol 13 (2) ◽  
pp. 168781402199497
Author(s):  
Guanghui Xu ◽  
Shengkai Su ◽  
Anbin Wang ◽  
Ruolin Hu
Keyword(s):  
Finite Element ◽  
Analytical Solution ◽  
Finite Element Simulation ◽  
Reaction Force ◽  
Vibration Reduction ◽  
Vertical Direction ◽  
Propagation Path ◽  
Track Structure ◽  
Test Results ◽  
Element Simulation

The increase of axle load and train speed would cause intense wheelrail interactions, and lead to potential vibration related problems in train operation. For the low-frequency vibration reduction of a track system, a multi-layer track structure was proposed and analyzed theoretically and experimentally. Firstly, the analytical solution was derived theoretically, and followed by a parametric analysis to verify the vibration reduction performance. Then, a finite element simulation is carried out to highlight the influence of the tuned slab damper. Finally, the vibration and noise tests are performed to verify the results of the analytical solution and finite element simulation. As the finite element simulation indicates, after installation of the tuned slab damper, the peak reaction force of the foundation can be reduced by 60%, and the peak value of the vertical vibration acceleration would decrease by 50%. The vibration test results show that the insertion losses for the total vibration levels are 13.3 dB in the vertical direction and 21.7 dB in the transverse direction. The noise test results show that the data of each measurement point is smoother and smaller, and the noise in the generating position and propagation path can be reduced by 1.9 dB–5.5 dB.

Finite Element Analysis of Reinforced Concrete Beams with Exterior FRP Shell

2011 ◽  
Vol 243-249 ◽  
pp. 1461-1465
Author(s):  
Chuan Min Zhang ◽  
Chao He Chen ◽  
Ye Fan Chen
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Contact Interface ◽  
Accurate Calculation ◽  
Element Analysis

The paper makes an analysis of the reinforced concrete beams with exterior FRP Shell in Finite Element, and compares it with the test results. The results show that, by means of this model, mechanical properties of reinforced concrete beams with exterior FRP shell can be predicted better. However, the larger the load, the larger deviation between calculated values and test values. Hence, if more accurate calculation is required, issues of contact interface between the reinforced concrete beams and the FRP shell should be taken into consideration.

scholarly journals Test and Numerical Model of Curved Steel–Concrete Composite Box Beams under Positive Moments

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2978
Author(s):  
Zhi-Min Liu ◽  
Xue-Jin Huo ◽  
Guang-Ming Wang ◽  
Wen-Yu Ji
Keyword(s):  
Finite Element ◽  
Static Loading ◽  
Composite Beams ◽  
Parameter Analysis ◽  
Outer Side ◽  
Finite Element Models ◽  
Test Results ◽  
Rotational Angle ◽  
Shear Connection ◽  
Box Beams

Compared with straight steel–concrete composite beams, curved composite beams exhibit more complicated mechanical behaviors under combined bending and torsion coupling. There are much fewer experimental studies on curved composite beams than those of straight composite beams. This study aimed to investigate the combined bending and torsion behavior of curved composite beams. This paper presents static loading tests of the full elastoplastic process of three curved composite box beams with various central angles and shear connection degrees. The test results showed that the specimens exhibited notable bending and torsion coupling force characteristics under static loading. The curvature and interface shear connection degree significantly affected the force behavior of the curved composite box beams. The specimens with weak shear connection degrees showed obvious interfacial longitudinal slip and transverse slip. Constraint distortion and torsion behavior caused the strain of the inner side of the structure to be higher than the strain of the outer side. The strain of the steel beam webs was approximately linear. In addition, fine finite element models of three curved composite box beams were established. The correctness and applicability of the finite element models were verified by comparing the test results and numerical calculation results for the load–displacement curve, load–rotational angle curve, load–interface slip curve, and cross-sectional strain distribution. Finite element modeling can be used as a reliable numerical tool for the large-scale parameter analysis of the elastic–plastic mechanical behavior of curved composite box beams.

The Study on Crashworthiness Performance of Thin-Walled Structures and the Effect of Welding Performance on it

2011 ◽  
Vol 63-64 ◽  
pp. 655-658
Author(s):  
Qi Hao ◽  
Sheng Jun Wu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Welded Joints ◽  
Impact Force ◽  
Deformation Energy ◽  
Optimal Shape ◽  
Explicit Finite Element Method ◽  
Explicit Finite Element ◽  
Thin Walled Structures ◽  
Thin Walled

Explicit finite element method is adopted to simulate the crashworthiness performance of four types of typical thin—walled structures used in vehicle by software LS-DYNA. The structures with the same material、area and length are crash by a rigid body with 40km/h in10ms, The crash processes and crashworthiness characters are analyzed by a series crash parameters: deformation energy with unit displacement, impact force and deceleration to look for the optimal shape with crashworthiness. With comparing, the double caps section has ascendant performance than the others. The simulating methods of welded-joints are discussed to analysis their effects on crashworthiness simulation.

Design of Static Test Model for Three-Tower Cable-Stayed Self-Anchored Suspension Composed Bridge

2011 ◽  
Vol 243-249 ◽  
pp. 1528-1535
Author(s):  
Yu Zhao ◽  
Yong Jun Zhou ◽  
Jing Sun ◽  
Jin Tao Tang ◽  
Xu Li
Keyword(s):  
Complex System ◽  
Finite Element ◽  
Element Model ◽  
Test Model ◽  
Test Results ◽  
Static Test ◽  
Whole Process ◽  
Aesthetic Appearance ◽  
Load Carrying ◽  
Novel Structures

Cable-stayed self-anchored suspension composed bridges have novel structures and aesthetic appearance with complex system and difficulty for design and construction. In order to acquire a better knowledge of the load-carrying capability of this type of bridges, based on a real bridge and the theory of abnormal similarity, a full-bridge scaled down(1:20) test model was built to simulate the whole process of construction. The test results were preferably fit the theoretical calculation value. It can be seen that the design of the bridge was reasonable, and the accuracy of the calculation of finite element model was verified at the same time. The test and the related results can be used as the reference for the test and design of the similar bridges.

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