Finite Element based Parametric Studies of a Truck Cab subjected to the Swedish Pendulum Test
Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
Scania has a policy to attain a high crashworthiness standard and their trucks have to conform to Swedish cab safety standards. The main objective of this thesis is to clarify which parameter variations, present during the second part of the Swedish cab crashworthiness test on a Scania R-series cab, that have significance on the intrusion response. An LS-DYNA FE-model of the test case is analysed where parameter variations are introduced through the use of the probabilistic analysis tool LS-OPT.
Example of analysed variations are the sheet thickness variation as well as the material variations such as stress-strain curve of the structural components, but also variations in the test setup such as the pendulum velocity and angle of approach on impact are taken into account. The effect of including the component forming in the analysis is investigated, where the variations on the material parameters are implemented prior to the forming. An additional objective is to analyse the influence of simulation and model dependent variations and weigh their respective effect on intrusion with the above stated physical variations.
A submodel is created due to the necessity to speed up the simulations since the numerous parameter variations yield a large number of different designs, resulting in multiple analyses.
Important structural component sensitivities are taken from the results and should be used as a pointer where to focus the attention when trying to increase the robustness of the cab. Also, the results show that the placement of the pendulum in the y direction (sideways seen from the driver perspective) is the most significant physical parameter variation during the Swedish pendulum test. It is concluded that to be able to achieve a fair comparison of the structural performance from repeated crash testing, this pendulum variation must be kept to a minimum.
Simulation and model dependent parameters in general showed to have large effects on the intrusion. It is concluded that further investigations on individual simulation or model dependent parameters should be performed to establish which description to use.
Mapping material effects from the forming simulation into the crash model gave a slight stiffer response compared to the mean pre-stretch approximations currently used by Scania. This is still however a significant result considering that Scanias approximations also included bake hardening effects from the painting process.
Place, publisher, year, edition, pages
Institutionen för ekonomisk och industriell utveckling , 2007. , 71 p.
Parametric Studies, Crash Analysis, Metamodel, Monte Carlo Analysis, Robust Design, Stochastic variations
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-8318ISRN: LIU-IEI-TEK-A--07/0061--SEOAI: oai:DiVA.org:liu-8318DiVA: diva2:23148
2007-02-12, IKP 3, A-huset, Linköpings Universitet, 581 83 LINKÖPING, 10:15
Lönn, DavidÖman, Michael