With which,it could be concluded that: corresponding with different train hardening rate and complex ratio,fracture form and mechanism could be changed;the position of maximum of stress triaxiality in blunted zone and maximum of shear stress in sharpened zone could be crack initiation position;the direction of maximum tensil.

This article reviews and summarizes the negative priming literatures in selective attention by the comparison of identity negative priming and location negative priming.

Study on fracture initiation pressure and fracture starting point in deviated wellbore with perforations;