二、轴心受拉构件的受力分析 4.混凝土开裂前拉力与变形的关糸 8=8=8 N1=A+、A (EA+E、A)E b E 13%时, E(A+A8 E E EA(1+58 e a 8二、轴心受拉构件的受力分析 4. 混凝土开裂前拉力与变形的关系 b h As A As /A3%时， A=bh l l Nt Nt Nt t As s l l t s  =  =  =        0 (1 ) ( ) ( ) E A A A E E E A A E E E A E A E A N A A c s c s c s c s c c s s t t s s = = + = + = + = +