Constitutive Models for Wave Propagation in Soils

2006 ◽  
Vol 59 (3) ◽  
pp. 146-175 ◽  
Author(s):  
Frederick Bloom
Keyword(s):  
Wave Propagation ◽  
Entire Range ◽  
Constitutive Models ◽  
Volume Distribution ◽  
Single Model ◽  
Function Model ◽  
Material Models ◽  
Elastic Plastic ◽  
Variable Modulus ◽  
Loading And Unloading

A survey is provided of the various constitutive models that have been used to study the phenomena of wave propagation in soils. While different material models have been proposed for the response of soils, it is now generally understood that no single model may be used over the entire range of pressures which are typically studied. The constitutive models reviewed in this paper include a number of effective stress and multiphase models, the volume distribution function model, and various versions of the P−α model. Also discussed are classical elastic-plastic models, models possessing different elastic constants in loading and unloading, variable modulus models, and capped elastic-plastic models.

Elastic-Plastic Boundaries in Combined Longitudinal and Torsional Plastic Wave Propagation

1968 ◽  
Vol 35 (4) ◽  
pp. 782-786 ◽  
Author(s):  
R. J. Clifton
Keyword(s):  
Wave Propagation ◽  
Time Derivative ◽  
Plastic Wave ◽  
Wave Speeds ◽  
One Dimensional ◽  
Elastic Plastic ◽  
Simple Waves ◽  
Thin Walled Tube ◽  
Loading And Unloading ◽  
All Speeds

Assuming a one-dimensional rate independent theory of combined longitudinal and torsional plastic wave propagation in a thin-walled tube, restrictions are obtained on the possible speeds of elastic-plastic boundaries. These restrictions are shown to depend on the type of discontinuity at the boundary and on whether loading or unloading is occurring. The range of unloading (loading) wave speeds for the case when the nth time derivative of the solution is the first derivative that is discontinuous across the boundary is the complement of the range of unloading (loading) wave speeds for the case when the first discontinuity is in the (n + 1)th time derivative. Thus all speeds are possible for elastic-plastic boundaries corresponding to either loading or unloading. The general features of the discontinuities associated with loading and unloading boundaries are established, and examples are presented of unloading boundaries overtaking simple waves.

Wave Propagation in One-Dimensional Structure of Periodic Inelasticity Composites

2011 ◽  
Author(s):  
Helio Aparecido Navarro ◽  
Meire Pereira de Souza Braun
Keyword(s):  
Wave Propagation ◽  
Vibration Suppression ◽  
Stop Band ◽  
Dimensional Structure ◽  
Material Models ◽  
One Dimensional ◽  
Elastic Plastic ◽  
Structural Problems ◽  
Plastic Damage ◽  
Non Linear

This study involves the analysis of elastic-plastic-damage dynamics of one-dimensional structures comprising of periodic materials. These structures are composed by multilayer unit cells with different materials. The dynamical characteristics of the composite material present distinct frequency ranges where wave propagation is blocked. The steady-state forced analyses are conducted on a structure constructed from a periodic inelasticity material. The material models have a linear dependence for elasticity problems and non-linear for elastoplasticity-damage problems. This paper discusses the pass and stop-band dispersive behavior of material models on temporal and spatial domains. For this purpose, some structural problems are composed of periodic and damping materials for analysis of vibration suppression have been simulated. This work brings a formulation of Galerkin method for one-dimensional elastic-plastic-damage problems. A time-stepping algorithm for non-linear dynamics is also presented. Numerical treatment of the constitutive models is developed by the use of return-mapping algorithm. For spatial discretization the standard finite element method is used. The procedure proposed in this work can be extended to multidimensional problems, analysis of strain localization, and for others material models.

The Effect of Material Constitutive Models on Stress Wave Propagation Calculations

1978 ◽  
Vol 100 (1) ◽  
pp. 84-95 ◽  
Author(s):  
W. Herrmann ◽  
R. J. Lawrence
Keyword(s):  
Wave Propagation ◽  
Finite Difference ◽  
Stress Wave ◽  
Constitutive Models ◽  
Material Model ◽  
Infinite Medium ◽  
Stress Wave Propagation ◽  
Material Models ◽  
One Dimensional ◽  
Design Calculations

Material models which have been successfully used for describing experimental observations of stress wave propagation in metals, polymers, composites, and porous materials are used in a series of one-dimensional finite-difference calculations of stress pulses propagating in a semi-infinite medium. These calculations show the effect of the material model on pulse attenuation. Parametric variations indicate the sensitivity of the attenuation to the parameters of each model. A simple conceptual description based on the hysteretic energy loss experienced by the material in a loading-unloading cycle is used to explain the results. Relevance of the results to the prediction of damage in specific engineering design calculations is developed. The results and conceptual description should aid the stress analyst in assessing which effects to include in the material model used in specific multidimensional calculations.

scholarly journals A novel semi-implicit scheme for elastodynamics and wave propagation in nearly and truly incompressible solids

2021 ◽  
Author(s):  
Chennakesava Kadapa
Keyword(s):  
Wave Propagation ◽  
Wave Speed ◽  
Critical Time ◽  
Incompressible Material ◽  
Implicit Scheme ◽  
Bulk Wave ◽  
Lumped Mass ◽  
Time Step ◽  
Material Models ◽  
Shear Wave Speed

AbstractThis paper presents a novel semi-implicit scheme for elastodynamics and wave propagation problems in nearly and truly incompressible material models. The proposed methodology is based on the efficient computation of the Schur complement for the mixed displacement-pressure formulation using a lumped mass matrix for the displacement field. By treating the deviatoric stress explicitly and the pressure field implicitly, the critical time step is made to be limited by shear wave speed rather than the bulk wave speed. The convergence of the proposed scheme is demonstrated by computing error norms for the recently proposed LBB-stable BT2/BT1 element. Using the numerical examples modelled with nearly and truly incompressible Neo-Hookean and Ogden material models, it is demonstrated that the proposed semi-implicit scheme yields significant computational benefits over the fully explicit and the fully implicit schemes for finite strain elastodynamics simulations involving incompressible materials. Finally, the applicability of the proposed scheme for wave propagation problems in nearly and truly incompressible material models is illustrated.

scholarly journals Effects of EOS and constitutive models on simulating copper shaped charge jets in ALEGRA

2019 ◽  
Author(s):  
Robert L. Doney ◽  
John H. J. Niederhaus ◽  
Timothy J. Fuller ◽  
Matthew J. Coppinger
Keyword(s):  
Threshold Stress ◽  
Equations Of State ◽  
Constitutive Models ◽  
Shaped Charge ◽  
Material Models ◽  
Us Army ◽  
Mechanical Threshold ◽  
The Us ◽  
Computational Resources ◽  
Experimental Diagnostics

Abstract Metallic shaped charge jets (SCJ) have been studied for many decades across multiple communities for applications ranging from military warheads to earth penetrators for accessing oil-rich areas [1]. Researchers have had varied success in modeling these jets using simulation codes such as CTH, ALEGRA, and ALE3D. Recently, a large amount of work has been performed at the US Army Research Lab investigating the behavior of jets with increasingly sophisticated experimental diagnostics. Advances in computational resources, code enhancements, and material models have allowed us to model jets and probe uncertainties caused by algorithms, equations of state (EOS), constitutive models, and any of the available parameters each one provides. In this work we explore the effects that various EOS and constitutive models have on the development and characteristics of a 65-mm diameter, 2D copper SCJ using the Sandia National Laboratories’ multiphysics hydrocode, ALEGRA [2]. Specifically, we evaluate the tabular SESAME 3320 [3], 3325 [4-5], and 3337 [6] EOS models, analytic EOS (ANEOS) 3331 [7], as well as the Johnson-Cook (JC) [8], Zerilli-Armstrong (ZA) [9], Preston-Tonks-Wallace (PTW) [10], Steinberg-Guinan-Lund (SGL) [11-12], and Mechanical Threshold Stress (MTS) [13] constitutive models. Note that while the SGL model supports rate-dependence, there is no current characterization for copper, thus we are using rate-independent version. We do not consider the MieGrüneisen equation of state here as we expect parts of the jet to be near or cross into melt.

Influence of service ageing on polyester-reinforced polyvinyl chloride-coated fabrics reported through mathematical material models

2018 ◽  
Vol 89 (8) ◽  
pp. 1472-1487
Author(s):  
Krzysztof Zerdzicki ◽  
Pawel Klosowski ◽  
Krzysztof Woznica
Keyword(s):  
Polyvinyl Chloride ◽  
Constitutive Models ◽  
Uniaxial Tensile ◽  
Creep Tests ◽  
Material Models ◽  
Material Parameters ◽  
Coated Fabric ◽  
Coated Fabrics ◽  
Term Creep

In this paper the coupled service (constructional tension) and environmental (sunlight, rainfalls, temperature variations) ageing influence on the polyester-reinforced polyvinyl chloride (PVC)-coated fabric VALMEX is studied. Two cases of the same fabric have been analyzed: one USED for 20 years on the real construction of the Forest Opera in Sopot (Poland), and one kept as a spare material (NOT USED). The following tests have been conducted: uniaxial tensile, biaxial tensile and long-term creep tests. The obtained results have been used for the parameter identification of the piecewise non-linear, Burgers and Bodner–Partom models. Next, the analysis of the influence of environmental conditions on the parameters of these models has been made. It has been concluded that some parameters are more and the others are less sensitive to the exposure to environmental and mechanical conditions. The change of material parameters for fill threads (due to larger deformation) is higher. The obtained results may be useful in the durability evaluation of the textile membranes reinforced with polyester threads and PVC coated. All the constitutive models with the identified parameters may be used for the numerical analysis of structures made of fabrics at the service beginning and after long-term usage.

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