Browsing by Author "Mulugeta, Hailemariam (Mr.) Co-Advisor"

Now showing 1 - 1 of 1
  • No Thumbnail Available
    Item
    Delamination of Composite Material Using Virtual Crack Closure Technique And Cohesive Zone Method for Automotive Structure and Semi-Structure
    (Addis Ababa University, 2017-11) Nebiyu, Abebe; Daniel, Tilahun (PhD); Mulugeta, Hailemariam (Mr.) Co-Advisor
    This paper studied Mode Ι delamination of Composite material using Virtual Crack Closure Technique and Cohesive Zone methods for Automobile Application. Quasi-Isotropic glass fiber/epoxy composite material is developed using Autodesk composite simulation design software. Mode Ι isotropic delamination propagation of quasi-isotropic composite material modeled on ABAQUS @ 10.14 for both Virtual Crack Closure Technique and Cohesive Zone methods. Virtual Crack Closure Technique with different mesh density as well different viscosity to overcome convergence difficulty are investigated. In Cohesive Zone method interface is assumed as damageable homogenous zero thickness layer of cohesive element between two composite layers. Load-Displacement curve is investigated by varying interfacial strength, penalty stiffness and viscosity to improve convergence by lowering either both or one, but excessively lowering is done taking care of over-softening. Design of quasi-isotropic composite with stacking sequence of [(-45 0 0 0 ,45 0 ,902 , 02 )2 ]s has Elastic modulus of 30900MPa, Shear modulus of 10300MPa and Poisson’s ratio of 0.293, using this material property critical delamination load and displacement are obtained from the analytical method , Virtual Crack Closure Technique and Cohesive Zone methods simulation are 32N,5.9mm and 32.35 N,4.9mm and 30.82N, 5.58mm respectively.