解:1)计算Fp、FNc 3)代入公式求位移 △Dv=[(5/6)(-4.2)×5+(-5/6)(-292)×5 +1X20×3+(23)(233)×4×2)/EA =2643×103m() 0=[(-5/24)-42)×5+(5/24)(-292)×5 +233×46-233×4/6/EA 3052×103) 8 Ax=0 A B FAX=O D Fp A 1 2 8 8解:１）计算FNP、FNC ３）代入公式求位移 DDV= [(-5/6)(-4.2)×5+(- 5/6)(-29.2)×5 +1×20×3+(2/3)(23.3)×4×2)]/EA = 2.643×10-3 m(↓)  = [（-5/24)(-4.2) ×5+(5/24)(-29.2)×5 +23.3×4/6-23.3 ×4/6 ]/EA = -3.052× 10-3 ()