ANISOTROPIC DAMAGE FOR CRASHWORTHINESS OF VEHICLES

A damage model for elasto-viscoplastic materials is presented. This model uses a microscopic approach, by means of the microvoid volume fraction evolution as growth, nucleation and coalescence. The microvoid is defined as an ellipsoid which can evolve in shape and direction according to the loading direction and the geometry of the structure. This model therefore considers the damage anisotropy by taking the microvoid shape effect into account. The anisotropy of the plastic behaviour is introduced into the model by means of the Hill 48 norm and the formulation of the damage model is consequently modified. The damage evolution law for the nucleation phase is also modified in order to introduce the damage part due to shearing. The use of the damage model means that the material parameters need to be identified and an identification process of the damage parameters is therefore defined by using an inverse method. This identification uses tensile tests of notched specimens cut in various directions in order to take the anisotropy of the damage into account, and an Arcan type tests which combine tensile and shear loadings. The latter, identifies the nucleation parameters controlled by the shear strains. Damage models are not well adapted for numerical simulations using a significant mesh size, such as those used in crash. Two solutions, which can be complementary, are therefore proposed to obtain a good representation of the rupture for large-sized elements. The first one consists of the use of an adaptive meshing technique and the second in the determination of new damage parameters according to the size of mesh considered. Bending tests with an aluminium extruded tube are then performed and give good correlations with experimental data. (A)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/13588265
• Corporate Authors:

  Woodhead Publishing, Limited

  Abington Hall, Abington
  Cambridge,   United Kingdom  CB1 6AH
• Authors:
  • CROIX, P
  • LAURO, F
  • BENNANI, B
• Publication Date: 2004

Language

• English

Media Info

• Features: References;
• Pagination: p. 299-309
• Serial:
  • International Journal of Crashworthiness
  • Volume: 9
  • Issue Number: 3
  • Publisher: Taylor & Francis
  • ISSN: 1358-8265
  • Serial URL: http://www.tandfonline.com/loi/tcrs20

Subject/Index Terms

• TRT Terms: Behavior; Crashes; Deformation; Isotropy; Loss and damage; Mathematical models; Plastics; Vehicles
• ITRD Terms: 9001: Behaviour; 1631: Collision; 1614: Damage; 5595: Deformation; 5917: Isotropic; 6473: Mathematical model; 7454: Plastic material; 1255: Vehicle
• Subject Areas: Vehicles and Equipment;

Filing Info

• Accession Number: 00976930
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: Aug 4 2004 12:00AM