论文部分内容阅读
一、COD方法是否有发展前途? 防止脆断办法,目前趋向于控制开裂而不搞止裂。这是因为许多研究工作证实:一般地说,钢材抗开裂性能比抗裂纹扩展性能好。控制止裂对材料要求过高,经济上不划算,而且止裂不能止漏泄。COD方法是在全面屈服情形下研究中低强度钢抗开裂性能的一种得力的方法。 COD方法的优点是: (1)在推导D-M模型的公式中,如计及焊接残余应力场就可预计残余应力的影响。同样也可计及预应变的影响。 (2)中低强度钢的COD试样可以作到比K_(1c)试样小一个数量级。
First, whether the COD method has a promising future? To prevent brittle fracture, the current tendency to control cracking without cracking. This is because many studies confirm: In general, steel anti-cracking performance than anti-crack expansion performance. Control of crack on the material requirements is too high, not economically cost-effective, and stop the leak can not stop leaks. The COD method is an effective method to study the cracking resistance of medium and low strength steel under the condition of total yield. The advantages of the COD method are: (1) In the formula for deriving the D-M model, the effect of residual stresses can be predicted, taking into account the residual stress field of welding. The same can also be taken into account the impact of pre-strain. (2) COD samples of medium and low strength steel can be smaller than K_ (1c) by one order of magnitude.