| Great error will come into being if we use conventional mechanics, and specially at the tip of the crack, high stress is the main factor which influences crack propagation. For reflective crack under repeat function of vehicle load , new conclusion can be gained if we take stress singularity at crack tip into account. It can be proved that the conclusion we get is close to the fact of road abruption. Therefore, it is very important to study the growing law of asphalt pavement using fracture mechanics method. The research can provide useful references for practical application.Based on the basic principle of fracture mechanics, the paper carries out systemic research on crack propagation in road structure using singular iso-parametric finite element, it is mainly formed by the several following parts.Discusses the stress singularity at crack, failure criterion, fatigue crack theory and computing method of fracture mechanics about crack . It includes and so on; process with the crack tips area by means of singular element method to reflact the stress singularity adequately;based on the computing method of singular iso-parametric finite element, analyzes and computes the question of finite element program of no crack model, one crack model and two crack model; discusses the spread principle of crack according to the corresponding pavement vehicle load response by means of anlysised symmetry load and insymmetry load opposite the place of crack; based on the summary of new research results in our country and the other countries, brings forward some engineering measures which can prevent the crack propagation of base course. All these will provide useful references for practical engineering application. |
PDF Full Text Request