Finite Element Analysis and Life Prediction of Pre-stressed Composed Dies in Cold Extrusion Process

2021 ◽  
pp. 2142001
Author(s):  
Zhen Zhang ◽  
Feng Yang ◽  
Xiawei Shao ◽  
Jiayuan Gu ◽  
Guangcheng Zha ◽  
...  
Keyword(s):  
Strain Energy Density ◽  
Strain Energy ◽  
Life Prediction ◽  
Inflection Point ◽  
Extrusion Process ◽  
Cold Extrusion ◽  
Element Analysis ◽  
Precision Forging ◽  
Cold Precision Forging ◽  
The Relationship

Improving and stabilizing the life of the die has always been the key to increasing the output of cold precision forging products and reducing the production cost of forgings. The stress state in pre-stressed composed dies during cold extrusion process is investigated in this paper, it shows that the combined die can greatly reduce the tangential tensile stress of the inner wall of the die and reduce the strain energy density of the die, thereby improving the strength of the die and extending the life of the die. By increasing the number of pre-stressed rings, the amount of interference can be changed, which indirectly changes the pre-stress applied to the die. The relationship between the die fatigue life and the number of pre-stressed rings indicates that the design of the pre-stressed composed structure above the inflection point is an excess design, and the optimal design should be near the inflection point.

Study on Cold Precision Forging of Non Straight Wall Cavity Piston

2011 ◽  
Vol 311-313 ◽  
pp. 2348-2352
Author(s):  
Ming Ming Ding ◽  
Ju Chen Xia ◽  
Lei Deng ◽  
Jun Song Jin
Keyword(s):  
Element Model ◽  
Cold Extrusion ◽  
Forming Process ◽  
Rigid Plastic ◽  
Precision Forging ◽  
Straight Wall ◽  
Cold Precision Forging ◽  
Overall Performance ◽  
Traditional Processing ◽  
Machine Processing

Brake piston is a huge demand non straight wall cavity part for the typical automotive industry; the traditional processing method is machine processing, or preforming by cold extrusion, and then machining. In this paper, the combined cold precision forging method of cold extrusion and spinning was proposed, which might improve the overall performance of parts and reduce costs. The rigid plastic finite element model of cold extrusion and spinning was established to simulate the forming process. The results showed that the combined cold precision forging method was available to manufacture non-straight wall cavity piston.

scholarly journals Low Cycle Fatigue Life Prediction Model of 800H Alloy Based on the Total Strain Energy Density Method

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 76 ◽  
Author(s):  
Wei Zhang ◽  
Tao Jiang ◽  
Liqiang Liu
Keyword(s):  
Prediction Model ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Fatigue Life Prediction ◽  
Cycle Fatigue ◽  
Total Strain Energy ◽  
Total Strain Energy Density ◽  
Life Prediction Model

In this paper, a high-temperature low-cycle fatigue life prediction model, based on the total strain energy density method, was established. Considering the influence of the Masing and non-Masing behavior of materials on life prediction, a new life prediction model was obtained by modifying the existing prediction model. With an 800H alloy of the heat transfer tube of a steam generator as the research object, the high-temperature and low-cycle fatigue test was carried out at two temperatures. The results show that the predicted and experimental results are in good agreement, proving the validity of the life prediction model.

Thermal Fatigue Prediction for Leadless Solder Joint of TFBGA

2006 ◽  
Author(s):  
Chia-Lung Chang ◽  
Tzu-Jen Lin ◽  
Chih-Hao Lai
Keyword(s):  
Energy Density ◽  
Solder Joint ◽  
Creep Strain ◽  
Thermal Fatigue ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Creep Property ◽  
Inelastic Strain ◽  
Temperature Cycling ◽  
Element Analysis

Nonlinear finite element analysis was performed to predict the thermal fatigue for leadless solder joint of TFBGA Package under accelerated TCT (Temperature Cycling Test). The solder joint was subjected to the inelastic strain that was generated during TCT due to the thermal expansion mismatch between the package and PCB. The solder was modeled with elastic-plastic-creep property to simulate the inelastic deformation under TCT. The creep strain rate of solder was described by double power law. The furthest solder away from the package center induced the highest strain during TCT was considered as the critical solder ball to be most likely damaged. The effects of solder meshing on the damage parameters of inelastic strain range, accumulated creep strain and creep strain energy density were compared to assure the accuracy of the simulation. The life prediction equation based on the accumulated creep strain and creep strain energy density proposed by Syed was used to predict the thermal fatigue life in this study. The agreement between the prediction life and experimental mean life is within 25 per cent. The effect of die thickness and material properties of substrate on the life of solder was also discussed.

Effects of Dwell-Time and Ramp-Rate on The Thermal-Fatigue Life of SnAgCu Joints

2005 ◽  
Author(s):  
Walter Dauksher ◽  
John Lau
Keyword(s):  
Finite Element Analysis ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Dwell Time ◽  
Cost Effective ◽  
Lead Free ◽  
Ramp Rate ◽  
Element Analysis ◽  
Thermal Environments ◽  
Thermal Fatigue Life

Finite element analysis examines lead-free part-on-board accelerated thermal environments comprised of ramp and dwell times lasting between 5 and 15 minutes. The accumulated creep strain energy density is determined for each environment and used to evaluate cost-effective accelerated test environments.

Failure Analysis of a Die for Cold Precision Forging of Bevel Gears

2008 ◽  
Vol 44-46 ◽  
pp. 779-786
Author(s):  
Jun Song Jin ◽  
Ju Chen Xia ◽  
Xin Yun Wang ◽  
Hua Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Element Analysis ◽  
Corner Crack ◽  
Premature Failure ◽  
Bevel Gears ◽  
Precision Forging ◽  
Bottom Hole ◽  
Cold Precision Forging ◽  
Reduce Stress Concentration

The life of bevel gear dies is determined by its stress state mainly. During the forging, the die teeth fractured and the bottom corner cracked in a few times. Finite Element Analysis (FEA) was employed to investigate the reason of failure. The results show that the tip fracture and the bottom corner crack mainly resulted from excessive tensile stress. In accordance with the FEA results, the non-plane parting face was changed into plane parting face and the radius of bottom hole was enlarged. The FEA result proves that the modification can greatly reduce stress concentration and the application proves that the modification can effectively solve the premature failure of the die.

Elastoplastic Plane Strain Analysis of Stresses and Strains at the Notch Root

1988 ◽  
Vol 110 (3) ◽  
pp. 195-204 ◽  
Author(s):  
G. Glinka ◽  
W. Ott ◽  
H. Nowack
Keyword(s):  
Energy Density ◽  
Plane Strain ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Notch Root ◽  
Equivalent Strain ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Energy Concept ◽  
Notch Tip

For the evaluation of the local elastoplastic strains and stresses at the notch root suitable approximation formulas of sufficient accuracy are often used. In the present study the “equivalent strain energy density” concept for elastic-plastic notch strain-stress analysis has been developed. It was found that the evaluation of the strain energy density in the notch tip plastic zones does not require any input data other than the material stress-strain relation and the elastic stress concentration factor. The concept was verified on the basis of the results obtained from plane strain elastic-plastic finite element analysis using the material model after Mro´z. Comparison of the two sets of results revealed satisfactory accuracy of the equivalent strain energy concept. It was also shown that all stress and strain components in the notch tip can be calculated by complementing the method with Hencky’s equations. Neuber-based calculations were also included in the study. It was found that the energy concept was superior to Neuber’s rule, especially in the presence of high inelastic strains in the notch tip.

Peridynamic Modeling of Hyperelastic Membrane Deformation

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
D. J. Bang ◽  
E. Madenci
Keyword(s):  
Energy Density ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Equations Of Motion ◽  
Uniaxial Loading ◽  
Density Functions ◽  
Loading Conditions ◽  
Element Analysis ◽  
Material Parameters ◽  
Loading Case

This study concerns the development of peridynamic (PD) strain energy density functions for a Neo-Hookean type membrane under equibiaxial, planar, and uniaxial loading conditions. The material parameters for each loading case are determined by equating the PD strain energy density to that of the classical continuum mechanics. The PD equations of motion are derived based on the Neo-Hookean model under the assumption of incompressibility. Numerical results concern the deformation of a membrane with a defect in the form of a hole, a crack, and a rigid inclusion under equibiaxial, planar, and uniaxial loading conditions. The PD predictions are verified by comparison with those of finite element analysis.

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