Experimental and numerical investigation of ductile damage Effect on load bearing capacity of a dented pipe with different internal pressure, wall thickness and indenter diameter

Akbari Alashti, Reza; Jafari, Sanaz; Hosseinipour, Seyed Jamal; Gorji, Abdol Hamid

Experimental and numerical investigation of ductile damage Effect on load bearing capacity of a dented pipe with different internal pressure, wall thickness and indenter diameter

Authors

Reza Akbari Alashti ¹

Sanaz Jafari ²

Seyed Jamal Hosseinipour ²

Abdol Hamid Gorji ²

¹ Mechanical Engineering Department Babol University of Technology

² School of Mechanical Engineering Babol University of Technology

Abstract

In this paper, the effect of ductile damage on the behavior of a dented pipe subjected to internal pressure is investigated by experimental and numerical methods. In the numerical investigation, the plastic behavior of pipes under indentation is studied using continuum damage mechanics theory and the elastic-plastic finite element analysis. Finite element calculations are carried out using the damage plasticity model proposed by Xue and Wierzbicki (X-W). The proposed damage plasticity model incorporates effects of four parameters that play important role in predicting the fracture initiation, namely the damage rule, the softening effect, the hydrostatic pressure and the Lode angle. The target dent depth is considered as an indication of the load bearing capacity of the pipe under indentation process by a rigid spherical indenter. To validate numerical calculations, a series of experimental tests are conducted on the API XB steel pipe with atmospheric pressure. After verification, numerical calculations for different ranges of internal pressures, wall thicknesses and indenter diameters with and without damage effect are carried out for aluminum 2024-T351 pipe and results are compared. It is shown that damage plays an important role on the load bearing capacity of an indented pipe. Results of the present study confirm the credibility of the proposed model in predicting the ductile fracture under multi-axial state of stress loadings.

Keywords

experimental test

Ductile damage

Indentation

Finite element analysis

Load bearing capacity