Stress transfer problems for a fully embedded fiber with a bonded interface and bonded ends

摘要

Stress transfer between fibers and matrix in fiber-reinforced composite was analyzed extensively using a shear lag model. Ends of the embedded fiber are generally assumed to debond from the matrix and stress transfer occurs only at the interface along the fiber length. The debonded ends are stress-free and the boundary condition at debonded ends in solving the stress transfer problem is trivial. When the fiber ends are bonded to the matrix, stress transfer also occurs at bonded ends, and the sress at bonded endsis finite. However, this finite stress is not a predetermined value, and the boundary condition at bonded ends becomes ambiguous. To resolve this ambiguity, a technique of adding imaginary fibers in the shear lag model is developed. Stress trnafer problems are analyzed when the composite is subjected to residual stresses or load. Comparison with experimental result is also made.