根据广义虎克定律: Ap,Hf18 L E +∑ 推导如下: 2≈△W●L A●E A△W静=W+W7-F-W =W+L(Ap-A)-(L-HA)A,P18 (Wr-LA, g) =A,p Hag .A=入,+,= App Hna Li L E Ari At根据广义虎克定律 ： ( ) 1 1 1 = = + m i r i i t p f A L A L E A  H g  推导如下：  = ( ) ( ) ( ) ( ) ' 1 = +   =  +  = =  − − = + − − −   = + − − •  •  = m i l f l r t p f l r r r p r f l p l r l s r At L Ari Li E Ap H g A H g W LA g W L A A L H A g W W W F W A E W L l 静