Wrinkling of an Unevenly Stretched Sheet Metal

1989 ◽  
Vol 111 (3) ◽  
pp. 235-242 ◽  
Author(s):  
Xiaofang Wang ◽  
L. H. N. Lee
Keyword(s):  
Finite Element Method ◽  
Sheet Metal ◽  
Strong Influence ◽  
Flexural Rigidity ◽  
Plastic Material ◽  
Yield Function ◽  
Material Parameters ◽  
Varying Thickness ◽  
Anisotropic Yield Function ◽  
Elastic Plastic Material

The onset of wrinkling of an unevenly stretched sheet metal subject to finite deformation is analyzed by an incremental finite element method. The sheet metal is modeled as a plate made of an elastic-plastic material. Hill’s anisotropic yield function and bifurcation criterion are employed in the analysis. The effects of geometrical and material parameters upon the onset of wrinkling are investigated. In the bifurcation analysis, attention is given to the changing and varying thickness of the sheet metal which could have a strong influence on the flexural rigidity of the sheet. Numerical results are presented herein.

A Contribution to the Optimisation of a Simple Shear Test

2009 ◽  
Vol 410-411 ◽  
pp. 467-472 ◽  
Author(s):  
Marion Merklein ◽  
M. Biasutti
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Shear Test ◽  
The Finite Element Method ◽  
Simple Shear Test ◽  
Material Parameters

The finite element method is a widely used tool in sheet metal forming. The quality of the results of such an analysis depends largely on the applied constitutive model and its material parameters, which have to be determined experimentally. These data are relevant on the choice of the yield criterion among the wide range of options available in the commercial applications implementing the finite element method. Since the accuracy of material parameters estimation is therefore crucial, investigations were performed with an Al-Mg sheet alloy and a mild steel sheet to optimize a Miyauchi-based simple shear test. This method is one of the basic ways to investigate the plastic properties of a sheet metal up to large strains, which is very important for numerical analysis of sheet metal forming processes. Aim of the test is to determine the shear stress-strain correlation. In order to enhance the quality of the experimental results the detection of the deformation’s field, trough an optical measurement system, and the methodology for its evaluation are focus of the present study.

scholarly journals Nonlinear Modeling and Identification of an Aluminum Honeycomb Panel with Multiple Bolts

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Yongpeng Chu ◽  
Hao Wen ◽  
Ti Chen
Keyword(s):  
Thin Layer ◽  
Plastic Material ◽  
Experimental Tests ◽  
Bolted Joints ◽  
High Excitation ◽  
Material Parameters ◽  
Elastic Plastic ◽  
Aluminum Honeycomb ◽  
Elastic Plastic Material ◽  
Honeycomb Panel

This paper focuses on the nonlinear dynamics modeling and parameter identification of an Aluminum Honeycomb Panel (AHP) with multiple bolted joints. Finite element method using eight-node solid elements is exploited to model the panel and the bolted connection interface as a homogeneous, isotropic plate and as a thin layer of nonlinear elastic-plastic material, respectively. The material properties of a thin layer are defined by a bilinear elastic plastic model, which can describe the energy dissipation and softening phenomena in the bolted joints under nonlinear states. Experimental tests at low and high excitation levels are performed to reveal the dynamic characteristics of the bolted structure. In particular, the linear material parameters of the panel are identified via experimental tests at low excitation levels, whereas the nonlinear material parameters of the thin layer are updated by using the genetic algorithm to minimize the residual error between the measured and the simulation data at a high excitation level. It is demonstrated by comparing the frequency responses of the updated FEM and the experimental system that the thin layer of bilinear elastic-plastic material is very effective for modeling the nonlinear joint interface of the assembled structure with multiple bolts.

scholarly journals Anisotropic Yield Function for Rocks and Evaluation of Material Parameters.

1999 ◽  
pp. 205-220
Author(s):  
Morito KUSABUKA ◽  
Hiroshi TAKEDA ◽  
Hiromi KOJO ◽  
Toru TONEGAWA
Keyword(s):  
Yield Function ◽  
Material Parameters ◽  
Anisotropic Yield Function

scholarly journals Heat generation due to friction in the shear crust zones as a factor of metamorphism and anatexis: the results of numerical simulation

2019 ◽  
Vol 486 (6) ◽  
pp. 704-708
Author(s):  
A. V. Babichev ◽  
V. V. Reverdatto ◽  
O. P. Polyansky ◽  
I. I. Likhanov ◽  
A. N. Semenov
Keyword(s):  
Friction Coefficient ◽  
Lower Estimate ◽  
Solid Mechanics ◽  
Plastic Material ◽  
Numerical Models ◽  
Shear Plane ◽  
Yield Function ◽  
Mechanical Equilibrium ◽  
Elastic Plastic Material ◽  
Horizontal Thrust

The heat release effect was estimated due to friction in faults under shear and thrust conditions by mathematical modeling, 3D and 2D thermomechanical numerical models were developed. The equations of solid mechanics in a coupled formulation were solved: the equations of mechanical equilibrium and the equation of heat transfer. The model of an elastic-plastic material with the Drucker-Prager and Huber-Mises yield function is used. For the 3D shear model, the heating was 100-110 °C for the value of the friction coefficient 0.3, 180-190 °C for 0.5, about 300 °C for 0.65. In models of horizontal thrust, the heating in the contact zone was 120-130 °C with a depth of shear plane of 20 km and 150-160 °C with a depth of shear plane of 30 km for a friction coefficient of 0.3. The results obtained can be considered as a lower estimate of the heating in the Yenisei collision-shear zone.

Effect of anisotropic yield function evolution on formability of sheet metal

2017 ◽  
Author(s):  
H. J. Choi ◽  
Y. Choi ◽  
K. J. Lee ◽  
J. Y. Lee ◽  
K. Bandyopadhyay ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Yield Function ◽  
Anisotropic Yield Function

Computer Simulation of Residual Stresses in Welding Process Using Finite Element Method

2008 ◽  
Vol 580-582 ◽  
pp. 439-442
Author(s):  
Shou Ju Li ◽  
Ying Xi Liu ◽  
Li Juan Cao ◽  
Zi Chang Shangguan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Residual Stresses ◽  
Plastic Material ◽  
Yield Criterion ◽  
Welding Process ◽  
Material Model ◽  
Elastic Plastic Material ◽  
Von Mises ◽  
Element Method

The prediction procedures of the residual stresses in welding process were presented by using finite element techniques. Owing to localized heating by the welding process and subsequent rapid cooling, the residual stresses can arise in the weld itself and in the base metals. The bilinear elastic-plastic material model based on Von Mises yield criterion was developed. The material nonlinearity of weldment and welding fluid was dealt with using an incremental technique. Inside each step, the Newton-Raphson iteration method was utilized. A fully coupled thermo-mechanical twodimensional analysis was performed with finite element method. The model applied in this study adopts the technique of element birth and death to simulate the weld filler variation with time in multi-pass welded joints. The effects of welding speed on residual stresses are discussed.

scholarly journals Influence of the elastic and elastic-plastic material parameters on the mechanical properties of slewing bearings

2021 ◽  
Vol 13 (1) ◽  
pp. 168781402199215
Author(s):  
Peiyu He ◽  
Yun Wang ◽  
Hong Liu ◽  
Erkuo Guo ◽  
Hua Wang
Keyword(s):  
Finite Element ◽  
Carrying Capacity ◽  
Plastic Material ◽  
Elastoplastic Material ◽  
Finite Element Models ◽  
Material Parameters ◽  
Load Carrying ◽  
Elastic Plastic Material ◽  
Critical Components ◽  
Slewing Bearings

Slewing bearings are critical components of rotating equipment. Large structure sizes and heavy working load conditions require an extremely high load-bearing capacity and reliability. Overall and local contact finite element models of slewing bearings are verified by the empirical formula and Hertz contact theory. Validated finite element models are used to analyse the influence of the elastic material (E 1) and elastoplastic material parameters (EP 1, EP 2 and EP 3) on the load carrying capacity. The following conclusions are obtained by comparing the maximum contact load, the contact stress, the load distribution and the full-circle deformation. The influence of the material parameters on the slewing bearing is investigated to improve the analysis accuracy of the carrying capacity of the slewing bearings.

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