Plastic Analysis of Metal Foam Core Sandwich Beam Transversely Loaded by a Flat Punch: Combined Local Denting and Overall Deformation

2012 ◽  
Vol 79 (4) ◽  
Author(s):  
Qing Hua Qin ◽  
T. J. Wang
Keyword(s):  
Metal Foam ◽  
Sandwich Beam ◽  
Plastic Behavior ◽  
Foam Core ◽  
Sandwich Beams ◽  
Low Velocity ◽  
Flat Punch ◽  
Rigid Plastic ◽  
Energy Impact ◽  
Impact Problems

The objective of this work is to investigate the quasi-static plastic behavior of a fully clamped metal foam core sandwich beam transversely loaded by a flat punch. A rigid-plastic beam-on-foundation model is extended to study the local denting deformation of a metal foam core sandwich beam. The effects of local denting and core strength on the overall deformation are incorporated in the analysis. Analytical solutions are derived for three different regimes of post-yield deformation mechanisms. Additionally, finite element results are obtained. Comparisons of the present analytical predictions with numerical, previous experimental, and analytical results are presented, respectively. It is shown that local denting has a significant effect on the finite deflection response of the metal foam core sandwich structure. The load-carrying and energy absorption capacities of sandwich beams may be overestimated if the effect of local denting is neglected in analysis. It is demonstrated that the present analytial model can reasonably predict the behaviors of post-yield deformation of sandwich beams. Moreover, the present analytical method can be extended to predict the low velocity/energy impact problems of sandwich structures.

A YIELD CRITERION AND PLASTIC ANALYSIS FOR PHYSICALLY ASYMMETRIC SANDWICH BEAM WITH METAL FOAM CORE

2013 ◽  
Vol 05 (04) ◽  
pp. 1350037 ◽  
Author(s):  
QINGHUA QIN ◽  
MINGSHI WANG ◽  
ZHENGJIN WANG ◽  
JIANXUN ZHANG ◽  
T. J. WANG
Keyword(s):  
Cross Sections ◽  
Metal Foam ◽  
Yield Criterion ◽  
Sandwich Beam ◽  
Sandwich Beams ◽  
Flat Punch ◽  
Fe Method ◽  
Core Strength ◽  
Beam Depth ◽  
Axial Stretching

A yield criterion for physically asymmetric sandwich cross-sections is proposed in this paper. Using the yield criterion, analytical solutions for the large deflections of fully clamped asymmetric slender sandwich beams transversely loaded by a flat punch at the midspan are derived considering the core strength effect and interaction of bending and axial stretching. Finite element (FE) method is employed to predict the large deflection behavior of the sandwich beams. Good agreement is achieved between the analytical predictions and FE results. Effects of asymmetric factor, core strength and loading punch size are also discussed. It is demonstrated that core strength and loading punch size have significant influences on the load-carrying and energy absorption capacities of physically asymmetric metal sandwich beams while the asymmetry effect could be neglected when the deflection exceeds sandwich beam depth.

Analytical Modelling of a Clamped Sandwich Beam under Impact Loading

2013 ◽  
Vol 535-536 ◽  
pp. 457-460
Author(s):  
Y. Liu ◽  
W.Z. Jiang ◽  
G.X. Lu
Keyword(s):  
Impact Loading ◽  
Complete Solution ◽  
Sandwich Beam ◽  
Small Deformation ◽  
Analytical Modelling ◽  
Coupling Mechanism ◽  
Foam Core ◽  
Sandwich Beams ◽  
Rigid Plastic ◽  
Projectile Impact

This paper examines a projectile impact on a fully clamped sandwich beams with foam core. By modeling the sandwich beam into two perfect rigid-plastic beams connected by perfect rigid-plastic springs, different coupling mechanism for the responses of the two beams are constructed so that a complete solution considering small deformation is derived.

A Comparison of the Structural Response of Clamped and Simply Supported Sandwich Beams With Aluminium Faces and a Metal Foam Core

2004 ◽  
Vol 72 (3) ◽  
pp. 408-417 ◽  
Author(s):  
V. L. Tagarielli ◽  
N. A. Fleck
Keyword(s):  
Metal Foam ◽  
Minimum Weight ◽  
Sandwich Beam ◽  
Limit Load ◽  
Analytical Models ◽  
Collapse Mechanism ◽  
Foam Core ◽  
Sandwich Beams ◽  
Polymer Foam ◽  
The Face

Plastic collapse modes for clamped sandwich beams have been investigated experimentally and theoretically for the case of aluminium face sheets and a metal foam core. Three initial collapse mechanisms have been identified and explored with the aid of a collapse mechanism map. It is shown that the effect of clamped boundary conditions is to drive the deformation mechanism towards plastic stretching of the face sheets. Consequently, the ultimate strength and level of energy absorption of the sandwich beam are set by the face sheet ductility. Limit load analyses have been performed and simple analytical models have been developed in order to predict the postyield response of the sandwich beams; these predictions are validated by both experiments and finite elements simulations. It is shown experimentally that the ductility of aluminium face sheets is enhanced when the faces are bonded to a metal foam core. Finally, minimum weight configurations for clamped aluminium sandwich beams are obtained using the analytical formulas for sandwich strength, and the optimal designs are compared with those for sandwich beams with composite faces and a polymer foam core.

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