(1.33)[AE,cosa'y+B,F,chay]'-Cchey+GEa.F1+u1+0E=Fi=式中(+的)cha()chaUC,为积分常数,由式(1.32)第二式之条件确定,即[A,q,' E,sina/ - B,a,Fisha,)]CPshp,d -(1.34)7sinpzd,j=1,2,3,..将式(1.33)进行逆变换,有2A,E,cosa/7+2[cch+B,F,chay]sinp,z(1.35)Z=3.求解节将式(1.29)代入式(1.23),有+4 B, 4.cosa,zsha,31cha,aacha,(1.36)S=B,cosa,()=士,:买苏仍用有限积分变换祛求解边值题(1.36).并取用如下积分变换式:(a,)[(,)cosad正变换:(1.37)(,)(a)co8a逆变换:aj,--(j--0. 5)x式中仿求解的方法,最后得2[≥AG,sing's - B,(L,shaj3 - H,jeha3) + ehe]acha,jcosa,z (1.38)aG.(1+a,Atha,)-1]、 Gn-式中L=u(a+a)cha,acna202a,cha'sinai1+0(cosaH,2ucha,a,ay=G-(a+)4.确定常数A.、B.及C.式(1.29)、(1.35)及(1.38)中A、B:和C尚是未知的,还需要确定.带数A、B,和C.之确定,除利用条件(1.34)外,尚须利用如下两个条件:2=±1, -1(墨+)(1.39)了=±人, &-1(墨+雾)(1.40)利用条件(1.34)、(1.39)及(1.40),最后得到确定带数A、B.和C,的如下线性代数方程组:6
BYuZc,p,N;cosp, - 0A.Xu--ZBY-B,12c,ppchp, --α. = 1.2.3...(1.41)台ZAX+ZB,Yy - C,pshPA - Z.1l式中 Xu-1 -Zp,Eacospe, Yiu --ZAFaPecosp., YupQuFachayAUZaGuMajsind,a, Yu, a,Ma(Lpsha,a - H,cha,a) - ajFasha,X,w[a,E,--ZaMathaa, Ma -sina-P) _ sintp), N, -2sche4ing?2. a β,a+p,+附)2a'cha,isina'aQu = sin(αB) + sin(a + P)Pi,-时)a+p,a. ,5.应力分量由求解式(1.41)之方程组确定常数A、B和C.后,代入式(1.29)、(1.35)和(1.38)中即可进行计算、和元,再将式(1.29)、(1.35)及(1.33)之2、和代入式(1.13)中,则得到如下应力分量的表达式cosaichaychaicosa'y22,E,cos3,zcosal3]+SAI0.-cha,ncha!o2,F,cosp,rcha3j+c.3.cosp,ieh.3A[chrcosacosa,zcha,y2a'Ggcos0,zcosa/3]+ a,=cha,acha'台acosa,icha.y+(a,L-H,)chay-H,ayshaycosa,z)--chajaa,G,sinaa/E,sinpsinal12ar ianheaiSB[ a(Lshay - Hiseha,y)sina,?Fa,sinazshay!2C.psinpzshe5+cna.A(1.42)(三)反对称荷载情形的解答将式(1.24)中之待确定函数g;()及g:()表示为如下级数形式:(1.43)AsinA'y, g(左) =B,cosa,rgi(y) =4(-0.5)元,/式中A:和B.为待定系数:仿求解对称荷载情形解答的方法和步骤,不难得到反对称荷载情形的解答。这里略去演算过程,直接给出有关的表达式和算式。7
1、、及节的表达式chgisinpiycosa,zsha,y+ B:Achp!sha,aZA.E,sinp!3+B.F,shay[C,shp+二sinzs47sina,cha,yZ[ZAGμcosP/ + B,(Lehajy -H,ysha,)asa.aj(1.44)B/E.!a.F.1+u2pshp'cosp1-0Eu=式中FEU(ch+门()shasin(a,p)sin(a)Gy2achB/sing1-0H,-时十-32sha,ati,3/G.1+vGit=[H,(sha, + a,icha) - 1],CU(ta)cha,sha,a确定带数A、B和C.的线性代数方程组2.B,Yu-Zc,p,N,cosP, = 0A,Xu1BLZB,Yuj - 2cpQshpA -- a i = 1.2.3...一(1.45)f-1A,X +ZB,Y+ C.BchPa=-Z.-i-1ZpiF,AP,cospa, YsX.-1-0EpFQushaApEucosp,Yu=式中0aGaMcosp,aX,EYuy - a,F,cha,a -a,M,(L,cha, -H,asha,a)47sina28!shp,cosaTa2ml+2. -N., =d+0sin(a-p)sin(r+ p,)2p'shadcos3Pu=-Maa-p.a+的+)sin(a; β,)sin(a, +3)Q, =P,=ira, + β,a-应力分量表达式AFcha/zsing+cosa,tsha,ya ia3 + 3/3ZAia.Achp!sha.ac..cosp,zshpye,Ficosp,shay++/cosa,isha,[chp!zsinp238CA'G,cosa,isinp'+chp!sha,a=a.cosa,ishan1.+ [a,L,sha:yH,(sha,y +ajchay)Jcoa,)2sha,a8
[EusinaGusinaJcos'B[a,sina,(L,cha,y - Hjsha,y) -aFysinptchay-5[gcha + 47sina sina,]c.p,sinp,zchpy+(1.46)Lsha,a利用上述解析解,我们对两端固定深梁的应力进行了其体的数值计算,计算分为两种情(1+v)(1-2u)形:一为深只受均布荷载9面无自惠,即g(1)=g70,并取。g=1.0UE1一1.0,0=0.167,计算结果绘在图1.3上,如实线所示者,另一为只有自重而无外教,即9(2)=0,并取>_(1+0)(1-20)g)Y=1.0,入-1.0,V=0.167计算结果绘在图1.4上,如实UE线所示。13130.5315(0.53)0.812.011. 001.000.000.280.000.00..41[(0.98)(0.75)(0.96)V(0.36)(0.01)(0.11)(0.07)DCP000. 0740.870.000.350.160.740.010.70(0.11)(0.87/(0.02)(0.05)(0.74)(0. 04)(0.73)(0.35)[(0. 18) ()?R+???0.010. 030.450.330.17,0.03030.441(0.01)(0.14)(0.02)F(0.06)(0.31)(0.42)(0.04)(0. 33)O-a.21?10.06田0.019o. 000.100.100.120.030. 28(0.06)103(0.02)(0.04)(0. 20)(0. 27)(0.01)0(0.10)(e.11)O田+0.32Jo.110.000.000.040. 00L000.001.0(0.29)0.101[(0.01)(0.00)(0,05)(0.01)(0.07)(0.51)(c)a分布阳(8),分布面,分有图(a)注:括号()内的懂为有限元结果图1.3尚塑应力分存团为了验证解析解的正确性,对上述两种荷载情形下两端固定深梁的应力,我们又采用有限元法进行了计算计算中利用问题的对称性,取深梁右半部分为计算对象,单元划分如困1.5所示,并利用SAP5程序进行计算.计算结果也分别绘在图1.3和1.4上,如虚线所示.由图可以看出,解析解与有限元结果吻合良好,证实了解析解的正确性。为了检验解析解中级数的收敛情况,我们在计算深梁只受均布外荷载的应力时,分别取级数前10、15、20.25、30项计算了=0.5截面上的应力。计算结果列于表1.1.1.2和1.3中.9
319.290. 000. 000.000, 00(0.39)0.101.540.00(0.14)(0.87)(1.71)(0.07)(0.00)(0.02)(0.19)(0.6$)COOOOO?0.010.5500.1610.160.G70.0710320. 58(0.16)(0.01)0.03)(0.54)(0. 93)(0.06)(0.10)(0.17))Hco.-SG,O??0.6300.000.0011.050.000. 00.000.30. 00(0.00)5(0.13)(0. 62)(10)(0.00)(0.00)(0.00)(0.00)(0. 00)0.16?0.170o.5500.070. 013.000.070. 980.16.03(0.10)(0.62)(0. 17)0.16)(0. 15)(0. 93)(0.01)(0. 05)000+④O?0.000. 290.000. 000.10No.000.000.76a(0.14)(0. 39)(0.03)(0. 65)(0.87)(1.71). [(0.07)(0. 05)(0. 19)r.分布国(e),分布图,分布图()a注:括号(内的值为有限元结果国1.4自量应力分布国4车事和务4年如车办元中鲜力+it4加?如图1.510