Finite element modeling mesh quality, energy balance and validation methods: a review with recommendations associated with the modeling of bone tissue.

https://roadsafellc.com/NCHRP22-24/Literature/Papers/Experiences%20in%20reverse-engineering%20of%20a%20Finite%20element%20automobile%20crash%20model.pdf

Experiences in reverse-engineering of a finite element automobile crash model

Fundamental principles controlling the deflection behavior of a simply supported beam responding to the impact action of a solid object is revealed in this paper. The significant mitigating effects that the mass of the beam have upon its impact resistant behavior have been illustrated with examples. It is a myth that the static resistance of the beam is indicative of its impact resistance. The important effects of "cushioning" and the higher modes phenomenon have also been identified by the analytical study presented herein. Hand calculations and computer analysis methods are introduced and evaluated by comparison with results obtained from finite element analyses using LS-DYNA.

Evaluation of simplified methods of estimating beam responses to impact

An innovative crashworthiness subfloor design concept was developed for middle or larger transport aircrafts. Closed-cell Rohacell-31 polymer foam blocks were introduced into the aircraft subfloor to enhance the energy absorption capability and mitigate peak acceleration during crash. Eight different configurations of foam blocks’ longitudinal distribution were considered. To provide a cost-effective method for assessing fuselage crashworthiness, compelling finite element models of an aircraft fuselage for these configurations were developed and vertical drops of the fuselage models were then simulated using the non-linear finite element code LS-DYNA. Impact responses, including failure behaviour, energy absorption and acceleration characteristics, were obtained and detailed effects of different foam block configurations on the crashworthiness was discussed. The analysis of the results showed that the optimal foam block length is 100–126 mm in our studied cases. The fuselage failure mode appeared to be sy...

Crashworthiness design of transport aircraft subfloor using polymer foams

This paper introduces the use of a two-degree-of-freedom (2DOF) model which comprises two spring-connected lumped masses for analyzing the response behavior of a plate structure to a low velocity impact of a flying solid object. We propose a novel method for calculating the value of the equivalent lumped mass and that of the spring constant which characterizes the 2DOF model. This is an important contribution given that existing calculation methods that are based on results from modal analysis would only be suitable for modeling the impact actions of wind or blast. Analysis involving the use of a 2DOF model is inexpensive and convenient to operate whilst achieving very good accuracies as demonstrated herein. By contrast, modeling impact response behavior by finite element analyses can be very time consuming and labour intensive because of the need to model in detail the impactor in contact with the target.

Estimation of response of plate structure subject to low veloctiy impact by a solid object

https://roadsafellc.com/NCHRP22-24/Literature/Papers/Experiences%20during%20development%20of%20a%20dynamic%20crash%20response%20automobile%20model.pdf

J. G. Thacker

Papers

Experiences in reverse-engineering of a finite element automobile crash model

Experiences during development of a dynamic crash response automobile model