Simulation of Responses of Liquid Filled Double Bottom Structures Subjected to a Closely Underwater Explosion Shock Loading

2011 ◽  
Vol 88-89 ◽  
pp. 662-667 ◽  
Author(s):  
Ting Tang ◽  
Li Jun Wang ◽  
Jin Bo Ma
Keyword(s):  
Finite Element ◽  
Shock Loading ◽  
Underwater Explosion ◽  
Finite Element Program ◽  
Explicit Finite Element ◽  
Comparative Analyses ◽  
Element Program ◽  
The Difference ◽  
Bottom Structures

The purpose of this work is to study the effect of liquid in double bottom structures subjected to a closely underwater explosion shock loading. The comparative analyses are made by use of a commercial, explicit finite element program. Based on the difference of depth of liquid in double bottom structures and distance between explosive and outer bottom, six cases were simulated in this paper. The results show that liquid in cabins can enhance the resistance of double bottom structures to an underwater explosion.

Virtual Testing for Frontal Impact of High-Top Cab of Heavy Truck

2011 ◽  
Vol 148-149 ◽  
pp. 1081-1084
Author(s):  
Wei Wang ◽  
Xu Liang Xie ◽  
Fu Lin Shen ◽  
Xiao Feng Wang
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Front Seat ◽  
Finite Element Program ◽  
Explicit Finite Element ◽  
Commercial Code ◽  
Element Program ◽  
Heavy Truck ◽  
Survival Space ◽  
Pendulum Impact

ECE R29 regulation has legally claimed that the survival space must be guaranteed for the safety for driver and front seat passenger in event of crash during design of truck cabin. In this paper, a finite element model of a high-top cabin of a heavy truck with a manikin on the driver seat was built with commercial code Hypermesh, The explicit finite element program Ls-Dyna was used to simulate the frontal pendulum impact on the high-top cab in the light of ECE R29 regulation. Deformation of the truck cabin and the survival space of the dummy were analyzed and discussed. Also, some suggestions were given to solve the contact possibility between steering column and the knees of manikin.

An Experimental and Numerical Study to Analysis and Design of Sheet Hydroforming Process for an Automobile Fender Shell

2006 ◽  
Author(s):  
Mohammad Habibi Parsa ◽  
Payam Darbandi
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Fluid Pressure ◽  
Finite Element Program ◽  
New Approach ◽  
Explicit Finite Element ◽  
Sheet Hydroforming ◽  
Analysis And Design ◽  
Hydroforming Process ◽  
Element Program

A new approach for manufacturing of shell fender is proposed and has been examined numerically and experimentally. The new suggested method is based on sheet hydroforming process, which has a lot of advantages over conventional deep drawing process. After defining the shape of initial blank using an inverse finite element program, numerical evaluation of the proposed sheet hydroforming process for production of shell fender has been carried out using an explicit finite element code considering fluid pressure, boundary conditions and tools. Then experimental evaluation has been carried out using down sized specimen and the results have been compared with results of previous simulations. It has been shown that there are similar trends between finite element and experimental results.

scholarly journals Fracture modelling of plain concrete using non-local fracture mechanics and a graph-based computational framework

2021 ◽  
Vol 477 (2252) ◽  
pp. 20210398
Author(s):  
P. Thamburaja ◽  
K. Sarah ◽  
A. Srinivasa ◽  
J. N. Reddy
Keyword(s):  
Finite Element ◽  
Plain Concrete ◽  
Element Analysis ◽  
Computational Framework ◽  
Finite Element Program ◽  
Explicit Finite Element ◽  
Element Program ◽  
Non Local ◽  
Material Length Scale ◽  
Material Length

In this article, we developed a thermodynamically consistent non-local microcracking model for quasi-brittle materials with application to concrete. The model is implemented using a novel graph-based finite element analysis (GraFEA) approach that allows for (i) the probabilistic modeling of the growth and coalescence of microcracks, (ii) the modeling of crack closure using a kinematics-based approach, and (iii) the modeling of rate effects on microcracking. The developed theoretical model and its computational framework is also implemented into the dynamics-based Abaqus/Explicit finite element program through a vectorized user-material subroutine interface. We further demonstrate the procedure for obtaining the parameters (including the non-local intrinsic material length scale, which governs the fracture process) and consequently validate the simulations with independent experimental results.

Optimal Configuration for Stiffened Plates under the Effect of Underwater Explosion

2015 ◽  
Vol 813 ◽  
pp. 161-168
Author(s):  
Fathallah Elsayed ◽  
Hui Qi ◽  
Li Li Tong ◽  
Mahmoud Helal
Keyword(s):  
Underwater Explosion ◽  
Optimal Configuration ◽  
Steel Plates ◽  
Floating Structure ◽  
Shock Loads ◽  
Finite Element Program ◽  
Explicit Finite Element ◽  
Element Program ◽  
Complex Fluid ◽  
Stiffened Steel

The dynamic response of a floating structure subjected to underwater explosion is greatly complicated by the explosion of a high explosive, propagation of shock wave, complex fluid–structure interaction phenomena, and the dynamic behavior of the floating structures. A numerical investigation has been carried out to examine the behavior of stiffened steel plates subjected to shock loads resulting from an Underwater Explosion (UNDEX). The aim of this work is to obtain the optimal configuration to resist underwater shock loading. A non-linear dynamic numerical analysis of the underwater explosion phenomena associated with different geometrical stiffened steel plates is performed using the ABAQUS/Explicit finite element program. Special emphasis is focused on the evolution of mid-point displacements. Further investigations have been performed to study the effect of including material damping and the rate-dependant material properties at different shock loads. The results indicate that stiffener configurations and shock loads affect greatly the overall performance of steel plates and sensitive to the material data.

Pipeline-Seabed Interaction in Soft Clay

2004 ◽  
Author(s):  
M. Hesar
Keyword(s):  
Finite Element ◽  
Soft Clay ◽  
Cost Effective ◽  
Fe Model ◽  
Adaptive Meshing ◽  
Lateral Buckling ◽  
Finite Element Program ◽  
Explicit Finite Element ◽  
Closed Form Solutions ◽  
Element Program

Offshore pipelines laid on the seabed in a snake configuration and transporting hydrocarbon products under high pressure/high temperature are becoming a cost effective alternative to trenching and burial. However, there appears to be a major disparity between the level of sophistication and accuracies inherent in the structural FE models used for expansion and lateral buckling analysis of pipelines, and the degree of crudity in adopting and using Coulomb friction values. This Paper reports the findings of a programme of geotechnical finite element analyses performed for a project where some 91km of 26” gas pipeline was designed to be laid in a snake configuration. The seabed soils were predominantly very soft clay. The ABAQUS/Explicit finite element program was used with an adaptive meshing technique to analyse the embedment and large lateral ploughing movements of the pipelines by a distance of several diameters. It was found that the FE model predicts the initial pipeline embedment into soil accurately and rectifies the inaccuracies inherent in published plasticity-based closed form solutions. A new non-dimensional relationship is proposed for estimating pipeline embedment in soft clays. The effect of important parameters such as the soil-pipeline interface friction, operating submerged weight and initial embedment, were all captured. Predicted cyclic lateral ploughing showed similarities to the observed response in reported model tests. The results were used in the structural FE model of the pipelines to analyse the expansion and lateral buckling problems and hence design the number and critical lay curvature of snakes as well as other important features.

scholarly journals The impact of drilling and slitting construction on damage field: evolution characteristics in low-permeability coal seam

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng
Keyword(s):  
Finite Element ◽  
Rock Mass ◽  
Damage Mechanics ◽  
Effective Strain ◽  
Secondary Development ◽  
Distribution Area ◽  
Finite Element Program ◽  
Element Program ◽  
Mining Face ◽  
The Impact

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.

Finite Element Analysis on the Deformation of Energy-Saving Wire-Mesh Frame Wallboard

2014 ◽  
Vol 501-504 ◽  
pp. 731-735
Author(s):  
Li Zhang ◽  
Kang Li
Keyword(s):  
Finite Element ◽  
Energy Saving ◽  
Theoretical Basis ◽  
Steel Wire ◽  
Wire Mesh ◽  
Design Parameters ◽  
Element Analysis ◽  
Finite Element Program ◽  
Element Program ◽  
Influence Degree

This paper analyzes the influence degree of related design parameters of wire-mesh frame wallboard on deformation through finite element program, providing theoretical basis for the design and test of steel wire rack energy-saving wallboard.

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