A New Complex-valued Thermal Fracture Finite Element Method for Evaluating the Structural Integrity of Aircraft Structures

摘要

A new computational method based on the complex-variable finite element method (ZFEM) is developed for composite materials and mixed mode loading. ZFEM is employed to calculate the Energy Release Rate (ERR) for linear elastic structures and materials undergoing thermal and mechanical loading. ZFEM allows easy and precise computation of the ERR as a byproduct of the finite element analysis and it overcomes some of the limitations of current fracture techniques such as the J-integral. In contrast to the J-integral. ZFEM is contourless and does not require corrective terms when extended into new physics. ZFEM facilitates structural integrity assessments of novel materials, such as composite and functionally graded materials. The results are compared against analytical and numerical solutions to verify the validity of the method. A practical application of the method is shown by conducting a fracture analysis of a skin/stringer panel under thermal and mechanical loading.