2B,*(Ss + 2ajly)sinag1"(2a'+tha/)+)2202uE2ca,S,sinagpha, --2D,P,rshp, + F,a/shal = 04E1ZB,Y,M, =- 1(1.133)i=1,2.3...E.p,chpaE2a'sina,a+a/tha/)-1.(1+a,itha,)-1,Ng式中X,Yα+2u2V2d ,sina,sin(a-p)sin(a,+p)2a,sina,QiR,=Pu-+品十号a-p,a,+β,2asina'asin[(a'--B/] sin[(a'+B,)A]T-S.aq/-pa+p,a+a由式(1.133)第三及第六式有2A.AaX,G;D,(1.134)1.2.3.YMQ1ZB:pehpE=Pchp.a将式(1.134)代人式(1.133)其余式中,有ZB,Yu - F,a,cha/ =- dn4.3元-ZA,Xu-2u0台ZAX + B 3元"- ZB,Y xy - C,a,cha, = - qs2u(1.135)F,2s "ZA,Xy, + BY,- ZB,Yu, + C,a,sha,a +-43行=1ZAXu-B,Yu,+ Zc,Zu,+ F,Aa,'sha/ m 0AXu-=1.2,32sina,aIx[ 2sino/ 2sinal*+CGaJuVacosegu式中Xu-aeaai-2sinaiyf 2sina, Asinat +ENaMycosp.quCM.Yu=Y910Yaa;Q:x,[2singgipa/-2P-Gycosp:], x -ZauRathBraXs=-5a,ay[2inasin +2mam]Yu(S+2a,a)singYaj20a,aXu, -#(Q, + 2a/ Ha) sina/a, Yy=1±(24a, + ha4)202vDY,RaMathp,a,Zai=ajQusina/achaf,Zua,Susina,cha,dYy-(2al+tha/),X-IxTaGthp!X.220于是,确定常数A、B、C、D.、E.和F,的问题,归结为先由式(1.135)之线性代数方程组36
确定常数A、BC.和F,然后再将求得的A和B.值代入式(1.134)计算D.和己,从而常数A、B.、C.、D、E,和F.便全部确定了。5.应力分量将式(1.125)、(1.127)及(1.130)代入式(1.13)得如下应力分量表达式:Fcha20cha'3ta/zahacosa/yacha20cha;E+1+ayshaschayC,a,cosa,ichay-cosaBchaacha,a2VD.p'chpizcospiy+D[hl+++szha/]cosa,3a行A1cha,2cha,SS1+uchay+ayshay!E.p.cosp.zchp.y+cosa120cha,a-OFa'chalzcosa'y+EEA,sha/+2a/chalsing'+ B,sha+achasincha,a212ucha;Casina,shaD/s/sinEsin,sh++F,a,'sha'isina'](1.136)(二)反对称荷载情形的解答方求解对称荷载情形解答的方法求解边值问题(1.53)(1.55),不难得到反对称荷载情形的解答。略去推导过程,将有关的表达式和算式书列于下。、和的表达式:1 .sha,jcosa,t2[4 + B.chp.sha,azche,zsinp,yZDsha/2sina/3-2C,sha,ysina,+ATchp,20B, Jcha,ysina,.sha,ashzcos1+0sE.chp.jcosp+F.chp'icosBychg!2V0+ B, 2ehacosa2]+ y-sha,a(1.137)式中α—0.5)元a=(i-0.5)/.=元,P/,A、B、CD、E和F为任意常数由下述方法确定。2.常数A~F,之确定37
先由如下线性代数方程组确定常数F:Ze,yu -- Fap?cha! - wwZD,Xu+ZE,Ys=-WaD,X, +C,a,sha,a+i-1Ney++ Nfzw-W.D,XCa,sha+-iALZc,Xu + Da/shai +SD,Y.ZEZu-FFLyshp,W----i=1,2,3..(1.138)I式中Yu-[+aNsba. a-.21+ag,S,-28/sing“好+明Xy, L2a,'sina,^YRA+PNa + 2ha,jshp,A, Uu=(a+tha,Aha:2u2/GyL(h) +2P)chaj, P,--22pthp,acospaYu=220-x阳+门(Us+ 2aMu)sinashXuy=a,Tysinachad,Zu=24A7cosBaYsinaif3-113-ua.Wu-生W.B!2U20ya1+u1(+ 240a)(3x - 427sing),W!42-co(thax20YR447sinar1+0102a,sina,ATm3V.-1921(Ua+2aMa)sina2uYa+sin[(a/ -β)a]sin(ai t p/a)2ha,sina'4a,a,sina,'xM.:G,-a,-β!++品(a+)thaH,-28/the/sina2(-)sina:sin(a, - + sin(a, + β)N-+(+)+3α, -P,sin[(q'-/]sin(α, -β)sinE(a: +p)sin(a;+B,)LiiR=apa+3a.-,a, +3,α,11++Y,=1X,-11-2utha,x)2V将所得带数I、和E.值代入下列公式计算常数A和B.:2Diaa1A. =i=1,2.3,...(1.135)447sina,)Ze,B,N,shp,A -B,=a,3.应分量38
chpiE1+ch/z+zsh/sineschp!20chp!I+a,ycha,yha.ycosazCa.cosa,zsha2usha,ashaa11"cha,zsina/y-ch1sinp'yche!2uche!-[sha,y1+usha,y+ajchayB.E.pcospashpycosa,zsha,a20S.A-p'chpzsinp'y+27y(h+2/ch1+r-1=A.20chp!B, (cha,3 + 2ayshay)sinaCa,sina,cha,ysha,aD,a, sha,Icosa'y-E3,sinch+F.pshpzcosp(1.140)到用上述解析解,我们对均布荷载9。作用下简支深梁的应力进行了计算。计算中取入一(1+0)(1-20)1.0.2=0.2,0=0.167.990=1.0.7=9/2.计算所得结果与31-3中用有E限积分变换法所得的结果相物合:1一7暑营深采的应分析如图1.22(a)所示悬臂深染,梁长为a,梁高为2b,梁的上边界受竖向分布荷载g(z),梁单位体积重为?,梁的受力为平面应力问题。7 (1)1(x)饭2.1:.1"→(a)(b)51.22取如图所示直解坐标系工oy,以梁长a为参考长度,在式1.10)无因次量的情形下,并将39
荷载q(z)转化为无因次量(z)=(1=2u)。q(.),测图1.22(a)成为图1.22(b),图UE中入=b/a.为了简化计算,将图1.22(6)之荷载分解为图1.23(a)和(6)所示关于轴对称和反对称的两种情形。1913(2)()瓷管管工17T1室理家厂4,(3)(I)(b)(a)[31.23在此情形下,控制方程与式(1.16)相同,根据问题之性质,有如下边界条件:对称荷载情形[图1.23(a),,01,, = 0,(1.141)-±, , =(),, = 0注意到式(1.13),条件(1.141)可写成巫=-2as0,=0,=0:=爱元(1.142)2(),n文二主人,a我ay同理,对反对称荷载情形[图1.23(6)西二一a-2.元=0,7=0,元=0元±=1,a(1.1:3)1洗ai-买一入-e于9)aJy()悬實深梁应力分析的边值问题综合控制方程(1.16)及边界条件(1.142)和(1.143),悬臂深梁的应力分折扫结为如下单个偏微分方程的边值问题:对称荷载情形图1.23(a)-01.(1.144)0f();=1,-f(),=±,f()!其中()()及f()为待确定之函数。1+02Vm2.(1.14c)元iah2-0,4=0:元-1,y=±入,y10