Temperature- and Rate-Dependent Failure in Dynamically Loaded Viscoplastic Materials

2012 ◽  
pp. 573-581
Author(s):  
Patrice Longère ◽  
Anne-Gaëlle Geffroy ◽  
Bruno Leblé ◽  
André Dragon
Keyword(s):  
Rate Dependent ◽  
Dynamically Loaded ◽  
Dependent Failure

Bovine annulus fibrosus hydration affects rate-dependent failure mechanics in tension

2019 ◽  
Vol 89 ◽  
pp. 34-39 ◽  
Author(s):  
Benjamin Werbner ◽  
Katherine Spack ◽  
Grace D. O'Connell
Keyword(s):  
Annulus Fibrosus ◽  
Failure Mechanics ◽  
Rate Dependent ◽  
Dependent Failure

A Technique to Characterize Rate-Dependent Failure Envelopes in Surface Mount Assemblies

2006 ◽  
Author(s):  
J. Varghese ◽  
A. Dasgupta
Keyword(s):  
Finite Element Analysis ◽  
Failure Strain ◽  
Nonlinear Finite Element ◽  
Element Analysis ◽  
Rate Dependent ◽  
Strain And Strain Rate ◽  
Failure Envelopes ◽  
Dependent Failure ◽  
Printed Wiring Assemblies

This paper characterizes the fatigue failure envelopes for solder damage in Printed Wiring Assemblies (PWAs) subjected to dynamic loading. An empirical, rate-dependent, power-law durability model, motivated by mechanistic considerations, is used to characterize the failure envelopes in terms of PWA flexural strain and strain rate. Explicit nonlinear finite element analysis (FEA) is used to make the damage constants independent of the specimen geometry and characterize the durability in terms of the ratio of solder plastic strain to its failure strain. A case study, using a simple PWA specimen containing a single area array component, is presented to demonstrate the proposed approach.

Vocal Fold Tissue Failure: Preliminary Data and Constitutive Modeling†

2004 ◽  
Vol 126 (4) ◽  
pp. 466-474 ◽  
Author(s):  
Roger W. Chan
Keyword(s):  
Preliminary Data ◽  
Vocal Fold ◽  
Large Strain ◽  
Deformation And Failure ◽  
Rate Dependent ◽  
Nonlinear Stress ◽  
Tissue Specimens ◽  
Dependent Failure ◽  
Tissue Stresses

In human voice production (phonation), linear small-amplitude vocal fold oscillation occurs only under restricted conditions. Physiologically, phonation more often involves large-amplitude oscillation associated with tissue stresses and strains beyond their linear viscoelastic limits, particularly in the lamina propria extracellular matrix (ECM). This study reports some preliminary measurements of tissue deformation and failure response of the vocal fold ECM under large-strain shear. The primary goal was to formulate and test a novel constitutive model for vocal fold tissue failure, based on a standard-linear cohesive-zone (SL-CZ) approach. Tissue specimens of the sheep vocal fold mucosa were subjected to torsional deformation in vitro, at constant strain rates corresponding to twist rates of 0.01, 0.1, and 1.0 rad/s. The vocal fold ECM demonstrated nonlinear stress-strain and rate-dependent failure response with a failure strain as low as 0.40 rad. A finite-element implementation of the SL-CZ model was capable of capturing the rate dependence in these preliminary data, demonstrating the model’s potential for describing tissue failure. Further studies with additional tissue specimens and model improvements are needed to better understand vocal fold tissue failure.

Adiabatic Shear Fractures and Fragments of Cylindrical Structures under Internal Explosive Loading

2011 ◽  
Vol 128-129 ◽  
pp. 367-372
Author(s):  
Li Ma ◽  
Yang Hu ◽  
Jian Xin ◽  
Gui De Deng
Keyword(s):  
Shear Fracture ◽  
Dynamical Evolution ◽  
Failure Criteria ◽  
Explosive Loading ◽  
Impulsive Loading ◽  
Adiabatic Shear ◽  
Critical Conditions ◽  
Cylindrical Structures ◽  
Rate Dependent ◽  
Dependent Failure

Adiabatic shear band (ASB) is a typical response of materials under high strain rate loading. Based on the instability analysis of the thermo-viscoplastic constitutive model, a new rate-dependent failure criteria is proposed, which links dynamical evolution of ASB with macro mechanical critical conditions, and is successfully applied to account for the shear fracture mode of cylindrical structures subjected to explosive loading. Using finite element method, the transient failure procedure and shearing fragments induced by ASB is simulated, and the calculated fracture profile shows a good agreement with the experimental results. The failure analysis indicates that the rate-dependent failure criteria, as well as impulsive loading, govern the shear damage mode of the structures.

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