| 查看: 1883 | 回复: 8 | ||
| 当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖 | ||
[求助]
多元非线性方程组求解，急求 已有1人参与
|
||
|
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 |
回复此楼» 猜你喜欢
重庆交通大学光子学微结构与器件课题组招收2026年硕士研究生信息
已经有2人回复
-
一志愿郑大材料学硕298分，求调剂
已经有6人回复
-
物理学I论文润色/翻译怎么收费?
已经有256人回复
-
寻合作：应力腐蚀多尺度模拟
已经有6人回复
-
考研交流
已经有0人回复
-
【新加坡】纳米电子器件项目组有“联合培养博士生”名额
已经有0人回复
-
【新加坡】纳米电子器件项目组有“联合培养博士生”名额
已经有0人回复
-
帮我的英语口语老师找学生
已经有3人回复
独孤神宇
版主 (知名作家)
- 应助: 490 (硕士)
- 贵宾: 0.008
- 金币: 31016.3
- 散金: 802
- 红花: 122
- 沙发: 1
- 帖子: 5600
- 在线: 856.5小时
- 虫号: 3522474
- 注册: 2014-11-06
- 性别: GG
- 专业: 机械动力学
- 管辖: 计算模拟
4楼2019-08-11 15:56:56
独孤神宇
版主 (知名作家)
- 应助: 490 (硕士)
- 贵宾: 0.008
- 金币: 31016.3
- 散金: 802
- 红花: 122
- 沙发: 1
- 帖子: 5600
- 在线: 856.5小时
- 虫号: 3522474
- 注册: 2014-11-06
- 性别: GG
- 专业: 机械动力学
- 管辖: 计算模拟
2楼2019-08-11 15:05:19
3楼2019-08-11 15:42:26
|
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
30