Modeling dynamic behaviour including shockwave propagation and spall failure in orthotropic materials

Ma'at, Norzarina (2017) Modeling dynamic behaviour including shockwave propagation and spall failure in orthotropic materials. Masters thesis, Universiti Tun Hussein Onn Malaysia.

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Abstract

In practice, most of the engineering materials manufactured using sheet metal forming processes, are orthotropic. The technological demands on such materials are coming from various manufacturing processes, aerospace structures, car crashworthiness and defence. Much research has been performed involving analytical, experimental and computational methods, it is generally accepted that there is still a need for improved constitutive models. Moreover, there are numerous mechanics of materials issues that have yet to be solved, related to finite strain deformation and failure of elastic and plastic of material orthotropic. Based on this motivation, a constitutive model is developed to predict a complex elastoplastic deformation behaviour involving shockwaves and spall failure in orthotropic materials at high pressure. The important feature of the proposed hyperelastic-plastic constitutive model formulated in this research project is a Mandel stress tensor combined with the new generalised orthotropic pressure. The formulation is developed in the isoclinic configuration and allows for a unique treatment for elastic and plastic part. The stress tensor decomposition of the new generalised pressure and Hill’s yield criterion aligned uniquely within the principal stress space is adopted to characterize elastic and plastic orthotropy. An isotropic hardening is adopted to define the evolution of plastic orthotropy. The formulation is further combined with a shock equation of state (EOS) and Grady spall failure model to predict shockwave propagation and spall failure in the materials, respectively. The algorithm of the proposed constitutive model is implemented as a new material model in the Lawrence Livermore National Laboratory (LLNL)-DYNA3D code of UTHM’s version, named Material Type 92 (Mat92). The

Item Type:Thesis (Masters)
Subjects:T Technology > TA Engineering (General). Civil engineering (General) > TA401-492 Materials of engineering and construction. Mechanics of materials
ID Code:9853
Deposited By:Mr. Mohammad Shaifulrip Ithnin
Deposited On:15 Mar 2018 15:18
Last Modified:15 Mar 2018 15:18

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