TRACING CRACK PROPAG ATION OF CONCRETE ACTED BY TRANSIENT TEMPERATURE FIELD

摘要

A model was set up using element-free method (EFM) to trace crack propagation of concrete acted byrntransient temperature field. The time-varying rules of temperature, stress and stress intensity factor atrnconcrete crack tip were analyzed to get the time of crack initiation and the whole process of crackrnpropagation. In addition the effects of the change rate of external temperature and crack depth on crackrnpropagation were discussed. The results show that surface crack can possibly develop into penetrative crackrnacted by variable external temperature, which would wreck structural stability, and surface crackrnpropagation is more likely to initiate in shorter period when the change rate of external temperature isrnhigher. What's more, the deeper crack is, and the easier and the rapider crack initiation are.