(上海交通大學國家模具CAD工程研究中心， 上海 200030)
摘 要: 以Lemaitre 的4個基本要素， 即損傷變量、 各向同性損傷假設、 有效應力、 應變等效性假設， 以及熱力學和損傷只發(fā)生在拉伸應力的塑性變形下的假設為基礎， 提出了一個韌性損傷準則， 它能解釋自由均勻鐓粗的自由表面無裂紋的現(xiàn)象。
關鍵字: 體積成形 韌性損傷 破壞準則
（Ji Guojin, Peng Yinghong and Ruan Xueyu）
Abstract:Based on Lemaitre's four basic elements, such as damage variable, hypothesis of isotropy, concept of effective stress and hypothesis of strain equivalence, and thermodynamics as well, and also on the author's hypothesis that damage can only be developed on plastic deformation with tensile stress, a new model of isotropic ductile damage was derived. The new model can explain that on the free surface of free homogeneous upsetting there is no ductile fracture.
Key words: metalforming ductile damage criterion of ductile damage
