Experimental Investigation and Finite Element Analysis of the Inversion of Capped End Frusta as Impact Energy Absorbers

Author(s):  
A. A. N. Aljawi ◽  
A. A. A. Alghamdi ◽  
T. M. N. Abu-Mansour

In this paper, an innovative mode of deformation of the frusta is presented and discussed in details. A full experimental investigation for the quasi-static axial inversion of right circular frusta is given. The experimental work includes studying the effect of frusta wall thickness, angle of frusta and material type on the inversion of the frusta. The quasi-static tests were conducted on an Instron Universal testing machine and qualitative dynamic test were carried using Drop Hammer Facility. Finite element (FE) modeling of the inversion mode is carried out by using ABAQUS FE package. Analysis of the deformation modes is examined using a non-linear model of the finite element package. The FE findings are reported and modes of deformation during the inversion of aluminum frusta are described under quasi-static and dynamic cases. Furthermore, a good agreement is reported between the finite element force histories and the experimental results.

2019 ◽  
Vol 823 ◽  
pp. 141-144
Author(s):  
Tung Sheng Yang ◽  
Yong Nan Chen

The feasibility of forging of AL-1050 alloy of cylindrical heatsink under warm conditions is demonstrated in the present work. The stress-strain curves and friction factor play an important role in the cylindrical heatsink forging. The purpose of forging lubrication is to reduce friction between blank and die, and to decrease resistance of metal flow to die. The stress-strain curves at different temperatures are obtained by compressing tests. The friction factor between 1050 aluminum alloy and die material are determined at different temperatures by ring compression tests with graphite lubricants. The compressing and ring compressing tests are carried out by using the computerized screw universal testing machine. The finite element method is used to investigate the forming characters of the forging process. To verify the prediction of FEM simulation in the cylindrical heatsink forging process, the experimental parameters such as stress-strain curves and fiction factor, are as the input data during analysis. Maximum forging load and effective stress distribution are determined of the heatsink forging, using the finite element analysis. Finally, the cylindrical heatsink parts are formed by the forging machine under the conditions using finite element analysis.


2015 ◽  
Vol 76 (9) ◽  
Author(s):  
Mohd Azman Y. ◽  
Juri S. ◽  
Hazran H. ◽  
NorHafiez M. N. ◽  
Dong R.

Dynamic response of ALPORAS aluminium foam has been investigated experimentally and numerically. The dynamic response is quantified by the force produced as the foam deforms as a function of time. Quasi-static tests are conducted to determine the quasi-static properties of the foam. In the impact test, the aluminium foams are fired towards a rigid load-cell and the force signals developed are recorded. Experimental dynamic stress is also compared with theoretical prediction using existing theory. Finite element model is constructed using LS-DYNA to simulate the impact test. Results from the experiment, finite element analysis and theoretical prediction are in acceptable agreement. Finally, parametric studies have been conducted using the verified model to investigate the effect of impact velocity and relative density towards the dynamic response of the foam projectile. It is found that the dynamic response of the foam is more sensitive towards impact velocity as compare with the foam relative density.


Author(s):  
Michiya Sakai ◽  
Ohtomo Keizo ◽  
Yutaka Hagiwara ◽  
Yoshihiro Dozono ◽  
Mayumi Fukuyama ◽  
...  

Hybrid simulation/testing systems have been developed incorporating a non-linear finite element method with a pseudo-dynamic test. In order to ensure stability and efficiency for time integration, the incremental formulation of the α-OS method has been implemented on this system. Visualization system has also been integrated to recognize both numerical simulation for whole systems and laboratory testing for local parts. Numerical hybrid examinations of the soil structure interaction problem have been conducted on this system. By these results, validity and effectiveness of this system has been demonstrated.


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