scholarly journals Identification of Nonlinear Dynamic Behavior and Failure for Riveted Joint Assemblies

2000 ◽  
Vol 7 (3) ◽  
pp. 121-138 ◽  
Author(s):  
B. Langrand ◽  
E. Markiewicz ◽  
E. Deletombe ◽  
P. Drazétic
Keyword(s):  
Sheet Metal ◽  
Constitutive Models ◽  
Numerical Procedure ◽  
Rate Sensitivity ◽  
Type Specimen ◽  
Metal Plate ◽  
Failure Behavior ◽  
Dynamic Experiments ◽  
Riveted Joint

Many different types of rivets need to be modeled to analyze the crashworthiness of aircraft structures. A numerical procedure based on FE modeling and characterization of material failure constitutive models is proposed herein with the aim of limiting the costs of experimental procedures otherwise necessary to obtain these data. Quasi-static and dynamic experiments were carried out on elementary tension (punched) and shear (riveted) specimens. No strain rate sensitivity was detected in the failure behavior of the riveted joint assemblies. Experimental data were used to identify the Gurson damage parameters of each material (2024-T351 and 7050 aluminum alloys for the sheet metal plate and the rivet respectively) by an inverse method. Characterization gave rise to satisfactory correlation between FE models and experiments. Optimized parameters were validated for each material by means of a uniaxial tension test for the sheet metal plate and an ARCAN type specimen in pure tension for the rivet.

Mechanical Properties and Modeling of Subcutaneous Adipose Tissue: a Comprehensive Review

2021 ◽  
Author(s):  
Zhaonan Sun ◽  
Bronislaw Gepner ◽  
Patrick S. Cottler ◽  
Sang-hyun Lee ◽  
Jason Kerrigan
Keyword(s):  
Mechanical Properties ◽  
Adipose Tissue ◽  
Constitutive Models ◽  
Rate Sensitivity ◽  
Material Behavior ◽  
Failure Behavior ◽  
Model Parameters ◽  
Comprehensive Review ◽  
Nonlinear Stress ◽  
Human Body Models

Abstract Mechanical models of adipose tissue are important for various medical applications including cosmetics, injuries, implantable drug delivery systems, and plastic surgeries, and biomechanical applications such as computational human body models for surgery simulation, and blunt impact trauma. This article presents a comprehensive review of experimental approaches that aimed to characterize the mechanical properties of adipose tissue, and the resulting constitutive models and model parameters identified. In particular, this study examines the material behavior of adipose tissue, including its nonlinear stress-strain relationship, viscoelasticity, strain hardening and softening, rate-sensitivity, anisotropy, preconditioning, failure behavior, and temperature dependency.

Calibration of Texture-Adjusted Strain-Rate Potential and its Application

2007 ◽  
Vol 340-341 ◽  
pp. 829-834
Author(s):  
Yi Ping Chen ◽  
Wing Bun Lee ◽  
Sandy To
Keyword(s):  
Sheet Metal ◽  
Crystal Plasticity ◽  
Plastic Anisotropy ◽  
Computing Time ◽  
Constitutive Models ◽  
Yield Function ◽  
Dislocation Slip ◽  
Texture Coefficients ◽  
Rate Dependent

An accurate prediction of plastic anisotropy induced by initial texture in sheet metal forming operations depends on the constitutive models adopted. Models of engineering interest include both phenomenological formulations and crystal plasticity based on dislocation slip. In addition to the above two approaches that are commonly adopted in FE analysis, now an alternative is available which describes anisotropic behavior of polycrystalline sheet metals still by an analytic yield function to keep the computing time as low as possible but at the same time which also takes explicitly into account the crystallographic texture of the material to give a more precise description of plasticity anisotropy. However, the locus of such a yielding potential determined by constitutive coefficients upon invoking the rate-independent crystal plasticity may exhibit an unrealistic concave shape, which will make it impossible to obtain a convergent solution. To circumvent the difficulty, a detailed computation procedure is presented to calculate the constitutive coefficients based on rate-dependent crystal plasticity. The combination of the coefficients obtained with experimentally measured texture coefficients of an annealed FCC polycrystalline sheet metal will provide a complete constitutive characterization of the material. As an application of the calibrated model, the process of deep drawing by hemispherical punch is simulated, in which plastic anisotropy (earring) corresponding to typical texture type is observed, thus demonstrating the applicability of the coefficients found.

Thermomechanical Response of Materials and Interfaces in Electronic Packaging: Part I—Unified Constitutive Model and Calibration

1997 ◽  
Vol 119 (4) ◽  
pp. 294-300 ◽  
Author(s):  
C. S. Desai ◽  
J. Chia ◽  
T. Kundu ◽  
J. L. Prince
Keyword(s):  
Laboratory Test ◽  
Constitutive Modeling ◽  
Electronic Packaging ◽  
Cyclic Fatigue ◽  
Failure Behavior ◽  
Thermomechanical Response ◽  
Disturbed State Concept ◽  
Test Behavior ◽  
New Criterion

The disturbed state concept (DSC) presented here provides a unified and versatile methodology for constitutive modeling of thermomechanical response of materials and interfaces/joints in electronic chip-substrate systems. It allows for inclusion of such important features as elastic, plastic and creep strains, microcracking and degradation, strengthening, and fatigue failure. It provides the flexibility to adopt different hierarchical versions in the range of simple (e.g., elastic) to sophisticated (thermoviscoplastic with microcracking and damage), depending on the user’s specific need. This paper presents the basic theory and procedures for finding parameters in the model based on laboratory test data and their values for typical solder materials. Validation of the models with respect to laboratory test behavior and different criteria for the identification of cyclic fatigue and failure, including a new criterion based on the DSC and design applications, are presented in the compendium paper (Part II, Desai et al., 1997). Based on these results, the DSC shows excellent potential for unified characterization of the stress-strain-strength and failure behavior of engineering materials in electronic packaging problems.

Nonlinear Vibration of Sheet Metal Plates Under Interacting Parametric and External Excitation During Manufacturing

2005 ◽  
Vol 127 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Chung Hwan Kim ◽  
Chong-Won Lee ◽  
N. C. Perkins
Keyword(s):  
Sheet Metal ◽  
Parametric Resonance ◽  
Parametric Excitation ◽  
Synergistic Effects ◽  
Broad Band ◽  
Metal Plate ◽  
Time Dependent ◽  
Single Frequency ◽  
Cubic Nonlinearity ◽  
External Excitation

This study is motivated by the vibrations that plague coating processes used in the manufacturing of coated sheet metal. These vibrations arise from time-dependent tension fluctuations within the sheet metal plate as well as from the eccentricity of the rollers used to transport the plate. The time-dependent tension is observed to be rather broad-band and creates multi-frequency parametric excitation. By contrast, the roller eccentricity is largely single-frequency (synchronized with the roller speed) and creates single-frequency external excitation. The plate and excitation sources are studied herein using a single-degree-of-freedom model with a cubic nonlinearity, subject to combined parametric and external excitation. In our study, we investigate the resonances that arise from the synergistic effects of multi-frequency parametric excitation and single-frequency external excitation. For the simpler case of single-frequency parametric excitation, we observe both sum and difference combination resonances in addition to principal parametric resonance. For the case of multi-frequency parametric excitation, we observe a frequency shift for the parametric resonance that derives from the cubic nonlinearity and external excitation. Moreover, the phase relationships of the external and each parametric excitation source have a significant effect on the resulting response amplitude. We use these analyses to explain the resonance mechanisms observed in experiments conducted on an example sheet metal coating process.

Characterization of Hyperelastic (Rubber) Material Using Uniaxial and Biaxial Tension Tests

2012 ◽  
Vol 570 ◽  
pp. 1-7
Author(s):  
Yawar Jamil Adeel ◽  
Ahsan Irshad Muhammad ◽  
Azmat Zeeshan
Keyword(s):  
Shear Test ◽  
Biaxial Tension ◽  
Constitutive Models ◽  
Hyperelastic Material ◽  
Strain Response ◽  
Stress Strain ◽  
Rubber Material ◽  
Tension Tests ◽  
Planar Shear

Hyperelastic material simulation is necessary for proper testing of products functionality in cases where prototype testing is expensive or not possible. Hyperelastic material is nonlinear and more than one stress-strain response of the material is required for its characterization. The study was focused on prediction of hyperelastic behavior of rubber neglecting the viscoelastic and creep effects in rubber. To obtain the stress strain response of rubber, uniaxial and biaxial tension tests were performed. The data obtained from these tests was utilized to find the coefficients of Mooney-Rivlin, Odgen and Arruda Boyce models. Verification of the behavior as predicted by the fitted models was carried out by comparing the experimental data of a planar shear test with its simulation using the same constitutive models.

Process Characterization of Sheet Metal Spinning by Means of Finite Elements

2007 ◽  
pp. 637-644
Author(s):  
Gerd Sebastiani ◽  
Alexander Brosius ◽  
Werner Homberg ◽  
Matthias Kleiner
Keyword(s):  
Finite Elements ◽  
Sheet Metal ◽  
Process Characterization ◽  
Metal Spinning

Fatigue characterization of a beam-to-column riveted joint

2019 ◽  
Vol 103 ◽  
pp. 95-123 ◽  
Author(s):  
António L.L. da Silva ◽  
José A.F.O. Correia ◽  
Abílio M.P. de Jesus ◽  
Miguel A.V. Figueiredo ◽  
Bruno A.S. Pedrosa ◽  
...  
Keyword(s):  
Riveted Joint

Based on the Finite Element Software ANSYS/LS-DYNA Metal Plate Covering Parts Forming Process Simulation and Optimization Research

2014 ◽  
Vol 912-914 ◽  
pp. 589-592
Author(s):  
Jin Ling Wang
Keyword(s):  
Finite Element ◽  
Sheet Metal ◽  
Metal Plate ◽  
Von Mises Stress ◽  
Skilled Workers ◽  
Forming Process ◽  
Simulation And Optimization ◽  
Finite Element Software ◽  
Stamping Process ◽  
Von Mises

The design of cold punching mould CAD/CAM and the combination of CAE analysis can advance analysis of stamping process program, eventually get ideal stamping parameters, realize design automation, save resources and reduce dependence on experience, reduce the demand for skilled workers. This paper, by using nonlinear dynamic finite element software ANSYS/ls-dyna continuous function, simulation of sheet metal forming process and unloading plate deformation, forming process, at any time throughout the von mises stress nephogram should rebound and strain values and unloading plate material as a result, analysis help us better understand the changes of the internal material sheet metal stamping process.

Characterization of enhanced low dose rate sensitivity (ELDRS) effects using Gated Lateral PNP transistor structures

2004 ◽  
Vol 51 (6) ◽  
pp. 3773-3780 ◽  
Author(s):  
R.L. Pease ◽  
D.G. Platteter ◽  
G.W. Dunham ◽  
J.E. Seiler ◽  
H.J. Barnaby ◽  
...  
Keyword(s):  
Dose Rate ◽  
Low Dose ◽  
Rate Sensitivity ◽  
Low Dose Rate

EFFECT OF TENSILE SPEED ON THE FAILURE LOAD OF A SPOT WELD UNDER COMBINED LOADING CONDITIONS

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1469-1474 ◽  
Author(s):  
JUNG-HAN SONG ◽  
HOON HUH ◽  
JI-HO LIM ◽  
SUNG-HO PARK
Keyword(s):  
Failure Load ◽  
Rate Sensitivity ◽  
Shear Loading ◽  
Spot Weld ◽  
Combined Loading ◽  
Failure Behavior ◽  
Loading Conditions ◽  
Dynamic Failure ◽  
Shear Loads ◽  
Failure Loads

This paper is concerned with the evaluation of the dynamic failure load of the spot weld under combined axial and shear loading conditions. The testing fixture are designed to impose the combined axial and shear load on the spot weld. Using the proposed testing fixtures and specimens, quasi-static and dynamic failure tests of the spot weld are conducted with seven different combined loading conditions. The failure load and failure behavior of the spot weld are investigated with different loading conditions. Dynamic effects on the failure load of the spot weld, which is critical for structural crashworthiness, are also examined based on the experimental data. In order to evaluate the effect of the strain rate on the failure contour of the spot weld under combined axial and shear loads, the failure loads measured from the experiment are decomposed into the two components along the axial and shear directions. Experimental results indicate that the failure contour is expanded with increasing strain rates according to the rate sensitivity of the ultimate stress for welded material.

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