第一題
(a)2度靜不定
(b)`delta=(4P)/(E*w)*((a*b)/(h*L))^3(darr)`
(c)
X=0~a
y=0~`+-h/2`
`sigma(x,y)=(12P*x*y)/(w*(h*L)^3)*[2X^3-4x^2*L+2x*L^2]`
`tau(x,y)=(6P)/(w*h*L^3)*[2x^3-3x^2*L+L^3]*[1/4-(y/h)^2]`
X=a~L
y=0~`+-h/2`
`sigma(x,y)=(12P*x^2*y)/(w*h^3*L^2)*[(2X^2)/L-4x+2L]`
`tau(x,y)=(6P*x^2)/(w*h*L^2)*[3-(2x)/L]*[1/4-(y/h)^2]`
第三題
(a)`phi(x)=(5P*x)/(G*a^3)=(25Px)/(2E*a^3)`
`theta(x)=-(1500Px)/(101E*a^4)*(x/2-10a)`
(b)`P_(cr)=(101*pi^2*E*a^2)/(600000)`
以上供參考,若有錯,請指正.謝謝!(跪拜禮new)
