Nonlinear Johnson Cook material constitutive model for high speed impact using finite element analysis

Ibrahim@Tamrin, Mohd Norihan (2017) Nonlinear Johnson Cook material constitutive model for high speed impact using finite element analysis. PhD thesis, Universiti Tun Hussein Onn Malaysia.

[img]PDF
13Mb

Abstract

It is known that ballistic impact and blasting are involving highly nonlinear material with large deformation in a very short duration. The conventional non-linear material constitutive laws that have been implemented nowadays would not be suitable on cluster parallel environment. In this research, a specific non linear material computational model with a distribution parallel capability have been searched and established. The Johnson Cook constitutive model was used as a basis while cluster parallel algorithm was proposed in the establishment of numerical simulation platform called CPIEA (Cluster Parallel Computing in Impact Engineering Application). Numerical simulations have been performed using IMPACT explicit finite element code. The preliminary mesh density evaluation was carried out in order to provide significant effect especially on the level of accuracy for the deformations process. The evaluation of parallel performance has been implemented through three phase of model namely simple model, multilayer model and complex model. The numerical model allows to predict accurately the impact failure mode depending on both projectile nose shape and impact velocity. The impact by using hemispherical nose shape of projectile towards target plate leads to the formation of petals around the perforated surface of the shell elements while multilayer shell elements represent widespread fragmentation of elements. The increase of impact velocity contribute positively on the hole enlargement of perforated surface. The complex model represent the projectile fully perforates the target with plug injection of elements. The study shows good agreements found between numerical and experimental results done by other researchers. The established simulation platform may provide an effective tool for simulating high speed impact and blast application especially on high-performance cluster parallel scalability. The parallel computation of impact cluster of projectile and target interaction and perforation using CPIEA platform are significantly improves the performance of execution time and speed up as the number of processors increases.

Item Type:Thesis (PhD)
Subjects:T Technology > TA Engineering (General). Civil engineering (General) > TA329-348 Engineering mathematics. Engineering analysis
ID Code:10267
Deposited By:Mr. Mohammad Shaifulrip Ithnin
Deposited On:13 Aug 2018 11:27
Last Modified:13 Aug 2018 11:27

Repository Staff Only: item control page