Predicting Composite Component Behavior Using Element Level Crashworthiness Tests, Finite Element Analysis and Automated Parametric Identification

Abstract

Fibre reinforced plastics have tailorable and superior mechanical characteristics compared to metals and can be used to construct relevant components such as primary crash structures for automobiles. However, the absence of standardized methodologies to predict component level damage has led to their underutilization as compared to their metallic counterparts, which are used extensively to manufacture primary crash structures. This paper presents a methodology that uses crashworthiness results from in-plane impact tests, conducted on carbon-fibre reinforced epoxy flat plates, to tune the related material card in Radioss using two different parametric identification techniques: global and adaptive response search methods. The resulting virtual material model was then successfully validated by comparing the crushing behavior with results obtained from experiments that were conducted by impacting a Formula SAE (Society of Automotive Engineers) crash box. Use of automated identification techniques significantly reduces the development time of composite crash structures, whilst the predictive capability reduces the need for component level tests, thereby making the development process more efficient, automated and economical, thereby reducing the cost of development using composite materials. This in turn promotes the development of vehicles that meet safety standards with lower mass and noxious gas emissions.

Design of a Lightweight Origami Composite Crash Box: Experimental and Numerical Study on the Absorbed Energy in Frontal Impacts

“…A modeling strategy embedding shell layers stacked with cohesive elements was first introduced in [14], where it is demonstrated to be capable of predicting the initiation and propagation of composite failure with an accuracy close to that of a solid elements model. In crash applications, cohesive elements were combined with solid [11,15] or shell [16] elements to model the response of large structures. The model presented in [15] combines cohesive with state-of-the-art techniques (e.g., fiber-oriented mesh, non-linear shear response, and tie-break controlled intra-laminar failure) to model the crash of a ±45 tube with remarkable accuracy but requires 94 h to reach 4 ms. Ref.…”

“…Ref. [16] adopted this strategy for modeling the crash of an IA, demonstrating its accuracy in the prediction of combined fragmentation and delamination of the structure. In this paper, shell and solid cohesive elements are combined to model the out-of-plane strength of the laminate.…”

Mechanical Behaviour of Pin-Reinforced Foam Core Sandwich Panels Subjected to Low Impact Loading

“…To create the FE model and appropriate element the mesh quality cannot be achieved directly. Therefore, a 3D CAD model was generated, and through the HYPERMESH software, the FE model was generated [34]. To reduce the computational time and simplification of the model a quarter of the model was generated.…”

Newly Developed Anti-Buckling Fixture to Assess the In-Plane Crashworthiness of Flat Composite Specimens

“…Table 2 reports material information about the used carbon-fiber-reinforced epoxy material, properties of which were obtained from characterization tests undertaken according to ASTM standards D3039 (tensile), D0790 (flexural), D3518 (shear), and D3410 (compression). The energy failure value and compressive and shear residual stresses were obtained by the use of an optimization technique developed by Garg et al [26]. The energy failure value is the W p described in Equation ( 1) and is one of the failure criteria available as part of the CRASURV model that retains the integrity of the element until the element absorbs energy equal to the failure value, after which softening takes place until the compressive and shear residual stress values shown in Table 2.…”