A new finite element model was developed to predict the density distribution in an Alumix 321 powder metallurgy compact. The model can predict the density distribution results of single-action compaction from 100 to 500 MPa compaction pressure. The model can also determine the amount of springback experienced by a compact upon ejection from the die at 100 and 300 MPa compaction pressure. An optical densitometry method, along with the creation of a compaction curve, was used to experimentally predict density distributions found within compacts, and found results that were consistent with both literature and finite element simulation. Further powder characterization included testing apparent density and flow rate of the powder. A literature review was also conducted and the results of which have been organized by three categories (powder type, material model, and finite element code) for easy reference by future powder researchers.

Thin-walled metallic components have been widely used as energy absorbers. One key drawback is the high initial crippling load, which typically results in passenger injuries. It is the objective of this study to introduce taper angle to thin-walled prisms, and to examine the crushing response of thin-walled frusta. Nonlinear finite element models of thin-walled frusta of different cross-sectional geometries were developed. Experimental investigations were conducted to validate these models. The effects of key design parameters on the energy absorption characteristics of frusta were explored. Comparison between thin-walled prisms and frusta show that taper angle helps to reduce the initial crippling load and increase the resistance to global buckling. To take advantage of the interaction effects, a novel multi-frusta configuration was developed and it was shown that the energy absorption efficiency is significantly increased. The results of this work are valuable for enhancing the crashworthiness performance of thin-walled metallic energy absorber.

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Thin-walled metallic components have been widely used as energy absorbers. One key drawback is the high initial crippling load, which typically results in passenger injuries. It is the objective of this study to introduce taper angle to thin-walled prisms, and to examine the crushing response of thin-walled frusta. Nonlinear finite element models of thin-walled frusta of different cross-sectional geometries were developed. Experimental investigations were conducted to validate these models. The effects of key design parameters on the energy absorption characteristics of frusta were explored. Comparison between thin-walled prisms and frusta show that taper angle helps to reduce the initial crippling load and increase the resistance to global buckling. To take advantage of the interaction effects, a novel multi-frusta configuration was developed and it was shown that the energy absorption efficiency is significantly increased. The results of this work are valuable for enhancing the crashworthiness performance of thin-walled metallic energy absorber.

No description available.