Browsing by Author "Brown, Jason C."
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Open Access Dynamic simulation of plastic components(Cranfield University, 2008-09) Chong, W. W. F.; Brown, Jason C.The aim of the study was to simulate the dynamic properties of automotive plastic materials for an FE analysis based on the Empirical Method. The study researched into the effects of strain rate and temperature on the stress-strain behavior of the material. The studied plastic material was DYLARK 480P16 produced by NOVA Chemicals. The stress-strain behavior of plastic materials used in the automotive industry was reviewed. The study included a review of the Eyring equation used to correlate the strain rate and temperature effects of the plastic materials. Lastly, the impact properties of plastic materials were briefly discussed in the study. Material models commonly used in the industry to represent plastic materials in LS-DYNA were reviewed. The overviews on Material 24 and Material 187 were presented in this study. The theory and parameters related to the development of these material models were briefly discussed. An overview on the physical tests for the study was included. The physical tests included UNIAXIAL Tensile and Drop Weight Impact tests. Drop Weight Impact test results were provided by Jaguar Cars Limited (JCL) for DYLARK 480P16. The Drop Weight Impact tests were conducted for test temperatures at ambient temperature 85oC and -40oC,. Finite element (FE) models simulating UNIAXIAL Tensile and Drop Weight Impact tests were produced in LS-DYNA. Material 24 was used to simulate DYLARK 480P16. The stress-strain related parameters for the material model were provided by JCL. The parameter of interest for the material model was the effect of Failure Plastic Strain (FPS) value. For Drop Weight Impact tests at temperatures -40oC and 85oC, the stressstrain parameters used for the ambient temperature simulation were scaled based on the Eyring equation and an additional correction factor. All simulation results for the Drop Weight Impact tests showed correlation to physical test results provided by JCL.Item Open Access A numerical study on the influence of internal corrugated reinforcements on the biaxial bending collapse of thin-walled beams(Elsevier, 2019-07-25) Vignjevic, Rade; Liang, Ce; Hughes, Kevin; Brown, Jason C.; De Vuyst, Tom; Djordjevic, Nenad; Campbell, James C.The Heat Treatment Forming and in-die Quench (HFQ) process allows for manufacturing of more complex geometries from Aluminium sheets than ever before, which can be exploited in lightweight automotive and aerospace structures. One possible application is manufacturing thin walled beams with corrugated internal reinforcements for complex geometries. This work considers different internal reinforcements (C-section and corrugated) to improve the energy absorption properties of thin walled rectangular beams under uniaxial and biaxial deep bending collapse, for loading angles ranging from 0 to 90 deg, in 15° increments. Using LS-DYNA simulations experimentally validated through unreinforced metallic tubes under quasi-static bending collapse, the finite element results demonstrate the stabilising effect of the reinforcements and an increase in the buckling strength of the cross section. Corrugated reinforcements showed a greater potential for increasing specific energy absorption (SEA), which was supported by investigating key geometric parameters, including corrugation angle, depth and number. This favourable response is due to an increased amount of material undergoing plastic deformation, which consequently improves performance of the beam undergoing post buckling and deep collapse. This concept is applicable to vehicle and aircraft passive safety, with the requirement that the considered geometries are manufacturable from Aluminium Alloys sheet only, using the HFQ process