Influences of Blank Holding Force on Stamping of Large Ellipsoidal Heads Based on Simulation

2012 ◽  
Vol 217-219 ◽  
pp. 2097-2100 ◽  
Author(s):  
Zheng Zhi Luo ◽  
Jing Zeng ◽  
Jin Peng Yu

Ellipsoidal heads is a important composition of railways tank car. Sheet stamping process is a common method used for manufacturing ellipsoidal heads. An accurate and efficient finite element model was developed for analysis and prediction of ellipsoidal heads forming quality, with different degrees of reduction deformation at different binder forces considered, and self-adaptive mesh were adopted to improve computational efficiency and quality. And the results of simulation was validated by experimental results. Based on this finite element model, the distributions of stress, strain and wall thickness during this process were obtained.

2010 ◽  
Vol 97-101 ◽  
pp. 337-343 ◽  
Author(s):  
Miao Jin ◽  
Shi Yan Zhao ◽  
Bao Feng Guo ◽  
Qun Li

Roll-over of crank arm is the major defect of forming quality during the upsetting process. Bending and upsetting forging of crankshaft was simulated by using the rigid-plastic finite element model. The theories of metal flowing and distribution of deformation during the bending and upsetting forging were analyzed, the root cause of the roll-over of crank was found; the optimal combination of the bending and upsetting velocities was obtained; the experimental results agree well with simulations.


2014 ◽  
Vol 501-504 ◽  
pp. 2479-2483
Author(s):  
Wei Bin Yuan ◽  
Chang Yi Chen

The flattening behaviour of angle section beams subjected to pure bending is studied in this paper. Analytical solutions for static instabilities of angle section beams subjected to pure bending about its weak axis are derived using energy methods. Nonlinear finite element model using the code ANSYS is developed to simulate nonlinear snap-through instability of angle section beams under pure bending. The optimization assumption about flattening shape of the leg is proposed, through comparison of between the present solutions, experimental results, and the finite element results.


2016 ◽  
Vol 858 ◽  
pp. 913-916 ◽  
Author(s):  
Konstantinos Zekentes ◽  
Konstantin Vassilevski ◽  
Antonis Stavrinidis ◽  
George Konstantinidis ◽  
Maria Kayambaki ◽  
...  

Purely vertical 4H-SiC JFETs have been modeled by using three different approaches: the analytical model, the finite element model and the compact model. The results of the modeling have been compared with experimental results on a series of fabricated self-aligned devices with two different channel lengths (0.3 and 1.1μm) and various channel widths (1.5, 2, 2.5, 3, 4 and 5 μm). For all the considered models I-V and C-V characteristics could be satisfactorily simulated.


Author(s):  
Neal P. Bitter ◽  
Joseph E. Shepherd

This paper analyzes the adequacy of shell models for predicting stresses and strains in thick-walled tubes subjected to detonation loads. Of particular interest are the large axial strains which are produced at the inner and outer surfaces of the tube due to bending along the tube axis. First, comparisons between simple shell theory and a static finite element model are used to show that the axial strain varies proportionally with wall thickness and inversely with the square of the axial wavelength. For small wavelengths, this comparison demonstrates nonlinear behavior and a breakdown of the shell model. Second, a dynamic finite element model is used to evaluate the performance of transient shell equations. This comparison is used to quantify the error of the shell model with increasing wall thickness and show that shell models can be inaccurate near the load front where the axial curvature is high. Finally, the results of these analyses are used to show that the large axial strains which are sometimes observed in experiments cannot be attributed to through-wall bending and appear to be caused instead by non-ideal conditions present in the experiments.


2015 ◽  
Vol 9 (1) ◽  
pp. 205-212 ◽  
Author(s):  
Fang Xiaoming ◽  
Yan Zhichao ◽  
Wang Liquan ◽  
Huang Yuxuan

Riser system is a key equipment for offshore oil and gas development. When conducting riser design, fatigue failure mode is the chief one among the many failure modes which should be taken into account. To assess the fatigue performance of riser accurately, it is necessary to conduct fatigue tests. Resonant bending fatigue test is one effective method for fatigue tests of risers. In this paper, the principle of resonant bending fatigue test and test procedures are presented firstly, and then a finite element model using ABAQUS is created to simulate the resonant bending fatigue test, and the results from the finite element model are compared with the experimental results. The good agreements between the FEM results and experimental results verify the accuracy of the finite element model in this paper.


2022 ◽  
Author(s):  
Zhen Jia ◽  
Xuan Wang ◽  
Yongping Shen ◽  
Yilian Xie ◽  
Xue Gong ◽  
...  

Abstract Spinning is widely used in aerospace and automobile industries, and non-axisymmetric spinning is developing with the increasing demand of irregular shape forming. Based on this, an avoidance groove at the middle of the tube (AGMT) which has potential application value in aircraft structure weight reduction is proposed and formed by using non-axisymmetric die-less spinning. The roller path is analyzed. The relationship between radial displacement of roller and the rotation angle of the tube is deduced. Based on the roller path, 3D finite element model is established. Then, the AGMT spinning experiment is carried out to verify the simulation results. The maximum deviation between the simulation and experimental results is less than 15%. It is indicated that the 3D finite element model established in this study is reliable and the method for the AGMT forming is feasible. The wall thickness and strain-stress distributions are analyzed. The severe wall thicken and thinning occur in the transition zones, so more attention should be paid to these positions. The depth of the groove has great impact on the forming quality. Deeper groove results in distortion and larger wall thickness difference. The research laid a foundation for the further development and optimization of the AGMT spinning.


2019 ◽  
Vol 92 ◽  
pp. 16002 ◽  
Author(s):  
Rukshan Azoor ◽  
Ravin Deo ◽  
Jayantha Kodikara

Corrosion is one of the major factors leading to the failure of buried pipelines. Soil properties such as aeration, moisture content and level of compaction are known to cause variations in the level of corrosion of buried metallic structures. It is known that, at a particular soil moisture content, the corrosion rate reaches a maximum value. While this phenomenon is generally understood, an explanation from a soil mechanics perspective with mechanisms for soil water continuity and mass transport processes is currently lacking. This work fills this void by modelling the moisture-controlled diffusion transport and electrical conductivity in soil coupled to the electrochemical activity on the buried metal surface. Variations in the electrical conductivity and oxygen diffusion in sand at different degrees of saturation were determined experimentally. The results were used as input parameters in a finite element model. Results from the coupled finite element model were compared with experimental results from electrochemical corrosion tests. The tests were conducted on cast iron specimen buried in sand and the corrosion behaviour under various aeration regimes were studied. The presence of an optimum moisture/aeration regime, where the corrosion rate becomes a maximum was demonstrated and the mechanisms behind this phenomenological behaviour are discussed in this paper. The modelling and experimental results are expected to be useful in developing non-intrusive testing methods for underground corrosion.


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