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[求助]
多元非线性方程组求解，急求 已有1人参与
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这个4元非线性方程组怎么解啊？急求各位大神 function f=fun(x0) syms x1 x2 x3 x4 x0=[x1 x2 x3 x4]; fi=0.515; fe=0.53; B=fi+fe-1; d=pi/180; a0=45*d; Db=7.144; Dm=40; n=1200; L=Db/Dm; Z=atan(10/(pi*40)); p=7.801e-6; E1=2.07e5; E2=1.9e5; u1=0.29; u2=0.305; Ro=17.15; Ri=24.294; ro=3.872; ri=3.872; g=x2/sin(x4)+x1/sin(x3); A1=B*Db*sin(a0)+g; A2=B*Db*cos(a0); w1=sin(x3)*(0.03*Db+x1); w2=A2-cos(x4)*(0.015*Db+x2); v=atan(sin(x3)/(L+cos(x3))); Wm=2*pi*n/(1+(1+L*cos(x3))*(cos(x4)+tan(v)*sin(x4))/((1-L*cos(x4))*(cos(x3)+tan(v)*sin(x3)))); Wr=-Wm*(1+L*cos(x3))*cos(Z)/(L*(sin(v)*sin(x3)+cos(v)*cos(x3))); Fc=(pi/12)*p*(Db^3)*Dm*(Wm^2); Mg=(1/60)*p*pi*(Db^5)*Wm*Wr*sin(v); Ps11=2/Db; Ps12=2/Db; Pn11=2/Db; Pn12=2/Db; Ps21=1/Ro; Pn21=-1/Ri; Ps22=-ro; Pn22=-ri; S1=Ps11+Ps12+Ps21+Ps22; S2=Pn11+Pn12+Pn21+Pn22; Rs1=Ps11*Ps21/(Ps11+Ps21); Rs2=Ps12*Ps22/(Ps12+Ps22); Rn1=Pn11*Pn21/(Pn11+Pn21); Rn2=Pn12*Pn22/(Pn12+Pn22); K1=1.0339*(Rs2/Rs1)^0.636; K2=1.0339*(Rn2/Rn1)^0.636; Ke1=1.5277+0.6023*log(Rs2/Rs1); Ke2=1.5277+0.6023*log(Rn2/Rn1); Ee1=1.0003+0.5968*(Rs1/Rs2); Ee2=1.0003+0.5968*(Rn1/Rn2); e1=(1-1/(K1^2))^0.5; e2=(1-1/(K2^2))^0.5; y1=(2*Ke1/pi)*((1-(e1)^2)*pi/(2*Ee1))^(1/3); y2=(2*Ke2/pi)*((1-(e2)^2)*pi/(2*Ee2))^(1/3); E=0.5*((1-u1^2)/E1+(1-u2^2)/E2); Q1=(8*(x1/y2)^3/((1.5*E)^2*S2))^0.5; Q2=(8*(x2/y1)^3/((1.5*E)^2*S1))^0.5; f1=(A1-w1)^2+(A2-w2)^2-(0.015*Db+x4)^2; f2=w1^2+w2^2-(0.03*Db+x3); f3=Q2*sin(x4)-Q1*sin(x3)-Mg/Db*(cos(x4)-cos(x3)); f4=Q2*cos(x4)-Q1*cos(x3)+Mg/Db*(sin(x4)-sin(x3))+Fc; f=[f1; f2; f3 ;f4]; % format long; % f=vpa(f,2); % class(f); end |
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3楼2019-08-11 15:42:26
独孤神宇
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2楼2019-08-11 15:05:19
独孤神宇
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4楼2019-08-11 15:56:56
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No solution found. fsolve stopped because the relative size of the current step is less than the default value of the step size tolerance squared, but the vector of function values is not near zero as measured by the default value of the function tolerance. <stopping criteria details> x1 = 0.264988629986718 - 0.227162298915769i 0.157276044576307 - 0.503604785301162i 53.759850087022613 - 0.866858320147245i 34.658568519774903 + 0.590132528775326i 得出的是这个，这不算求出解啊 |
5楼2019-08-11 16:51:12
6