103构件受冲击时的应力与变形(103) 4、杆件受到竖向冲击 U=△U=P(h+△a)T=△T=0 =W=-P△ U+T=v 2 E,A h P(h+△)=P△ P P EA EA P(h+△)=P →△2-2△2△2-2△2h=0( ) U U P h =  = + d 1 2 V W P  d d d = =  1 ( ) 2 P h P +  =  d d d , d st d Pl P l EA EA  =  = 2 1 ( ) 2 d d st P h P  +  =  d d st P P  =  2 st st 2 2 0 d d  −   −  h＝ P E A, d h Pd 10.3 构件受冲击时的应力与变形（10.3） 4、杆件受到竖向冲击 T T =  = 0 U T V + = d