Modeling dynamic deformation and failure of thin-walled structures under explosive loading

Ivan Volkov,Svetlana Litvinchuk,Leonid Igumnov,Igor Vorobtsov,E Buzaud,H Couque,E Cadoni,A Cosculluela

doi:10.1051/epjconf/201818303016

Ivan Volkov, Svetlana Litvinchuk + Show 6 more

Open Access

https://doi.org/10.1051/epjconf/201818303016

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Abstract

In the framework of mechanics of damaged media, behavior of thin-walled structures under pulsed loading is described. Account is taken of the interaction of the processes of dynamic deformation and damage accumulation, as well as of the main characteristic features of the dynamic failure process: the multi-staged character, nonlinear summation of damage, stressed state history and accumulated damage level. The chosen system of equations of thermo-plasticity describes the main effects of dynamic deformation of the material for random deformation trajectories. The equations of state are based on the notions of yield surface and the principle of gradientality of the plastic strain rate vector. Evolutionary equations of damage accumulation are written for a scalar parameter of damage level and are based on energy principles. The effect of the stressed state type and the accumulated damage level on the processes of nucleation, growth and merging of microdefects is accounted for. Results of numerically modelling processes of dynamic deformation and failure of spherical and closed cylindrical shells with plane and hemispherical bottoms under single pulsed explosive loading are presented. The computational results are compared with experimental data.

Highlights

One of the main tasks of mechanical engineering is to substantiate the operational resource of the machinery being designed, to evaluate spent resource and to predict residual resource of its structural units in the process of its exploitation, and to prolong service life of objects which have spent their rated resource
Explosive expansion of shells and rings is a unique tool for studying a number of issues of dynamic theory of plasticity and failure mechanics
Worth mentioning are the investigations based on the concept of damaged media, in which failure of objects is described as a process of accumulation of microdefects, [7,8,9]. Such approaches open a possibility of globally modeling failure processes, accounting for the effect of the damage level on the deformational characteristics of materials, and its dependence on the history of loading and temperature, with including the damage level into the analysis of service life of structures

Summary

Introduction

One of the main tasks of mechanical engineering is to substantiate the operational resource of the machinery being designed, to evaluate spent resource and to predict residual resource of its structural units in the process of its exploitation, and to prolong service life of objects which have spent their rated resource. Explosive expansion of shells and rings is a unique tool for studying a number of issues of dynamic theory of plasticity and failure mechanics This problem has purely a practical application connected with the. Worth mentioning are the investigations based on the concept of damaged media, in which failure of objects is described as a process of accumulation of microdefects, [7,8,9] Such approaches open a possibility of globally modeling failure processes, accounting for the effect of the damage level on the deformational characteristics of materials, and its dependence on the history of loading and temperature, with including the damage level into the analysis of service life of structures. The reliability of the developed defining relations of MDM was assessed by comparing the experimental and numerical data on the dynamic deformation and failure of spherical and cylindrical shells under internal explosive loading [10, 11], which corroborated the adequacy of modeling and determining material parameters

Defining relations of damaged medium mechanics

Investigation results

Conclusion