The strain energy density function equals the Helmholtz. 应变能密度函数等于亥姆霍兹函数。
Multiaxial fatigue life prediction methods are concentrated, in which critical-plane strain energy density criteria seem to be the most promising. 主要评述各种多轴疲劳寿命估算方法,其中临界面应变能密度法是较为有效的方法。