V3 =LABW1 COSΦ1 ④ a3 =-LABW12 sinΦ1 ⑤ (2)确定惯性力:F12=m2as2=(G2/g)LABW12 ⑥ F13=m3a3=(G3/g)LABW12sinΦ1 ⑦
(3)各构件的平衡方程: 构件3:∑Fy=0,FR23 =Fr-F13 ∑Fx=0,FR4’=FR4
∑MS3 =0,FR4=FR23LA cosΦ1/h2 构件2:∑Fx=0,FR12x=F12cosΦ1
∑Fy=0,FR12y=FR32-F12sinΦ1 构件1: ∑Fx=0,FR41x=FR12x ∑Fy=0,FR41y=FR12y ∑MA =0,Mb =FR32LABcosΦ1 总共有八个方程,八个未知数。 归纳出一元八次方程矩阵:
1 0 0 0 0 0 0 0 FR23 Fr-F13 0 1 -1 0 0 0 0 0 FR4’ 0 -LABCOSΦ1/h2 0 1 0 0 0 0 0 FR4 0 0 0 0 1 0 0 0 0 FR12x = F12cosΦ1 -1 0 0 0 1 0 0 0 FR12y -F12 sinΦ1 0 0 0 -1 0 1 0 0 FR41x 0 0 0 0 0 -1 0 1 0 FR41y 0 -LABCOSΦ1 0 0 0 0 0 0 1 Mb 0
AX=B进而可得:X=A\\B。
接下来运用软件工具进行分析。
1、进行MATLAB编程分析
首先编写函数F用于实现上述运算功能: function y=F(x) %
%input parameters %
%x(1)=lAB %x(2)=h1 %x(3)=h2 %x(4)=W1 %x(5)=G2 %x(6)=G3 %x(7)=Fr
%x(8)=theta1 %
%output parameters
16
%
%y(1)=FR23 %y(2)=FR4' %y(3)=FR4 %y(4)=FR12x %y(5)=FR12y %y(6)=FR41x %y(7)=FR41y %y(8)=Mb %
A=[1 0 0 0 0 0 0 0; 0 1 -1 0 0 0 0 0;
-x(1)*cos(x(8))/x(3) 0 1 0 0 0 0 0; 0 0 0 1 0 0 0 0; -1 0 0 0 1 0 0 0; 0 0 0 -1 0 1 0 0; 0 0 0 0 -1 0 1 0;
-x(1)*cos(x(8)) 0 0 0 0 0 0 1];
B=[x(7)-(x(6)/10)*x(1)*x(4)^2*sin(x(8));0;0;(x(5)/10)*x(1)*x(4)^2*cos(x(8));-(x(5)/10)*x(1)*x(4)^2*sin(x(8));0;0;0];
y=A\\B;
接下来运行程序计算Φ1=60°的各未知量值: lAB=0.1; h1=0.120; h2=0.08; W1=10; G2=40; G3=100; Fr=400;
th1=60*pi/180;
x=[lAB h1 h2 W1 G2 G3 Fr th1]; y=F(x) y =
313.3975 195.8734 195.8734 20.0000 278.7564 20.0000 278.7564
17
15.6699
得到:Φ1=60°时FR23=FR32=313.3975 N;FR4=FR4’=195.8734 N;FR12x=20.0000 N;FR12y=278.7564 N;FR41x=20.0000 N;FR41y=278.7564 N;Mb=15.6699 N*m。
运行程序计算Φ1=150°的各未知量值: >> th1=150*pi/180;
>> x=[lAB h1 h2 W1 G2 G3 Fr th1]; >> y=F(x) y =
350.0000 -378.8861 -378.8861 -34.6410 330.0000 -34.6410 330.0000 -30.3109
得到:Φ1=150°时FR23=FR32=350.0000 N;FR4=FR4’=-378.8861 N;FR12x=-34.6410 N;FR12y=330.0000 N;FR41x=-34.6410 N;FR41y=330.0000 N;Mb=-30.3109 N*m。
运行程序计算Φ1=220°的各未知量值: >> th1=220*pi/180;
>> x=[lAB h1 h2 W1 G2 G3 Fr th1]; >> y=F(x) y =
464.2788 -444.5727 -444.5727 -30.6418 489.9903 -30.6418 489.9903 -35.5658
得到:Φ1=220°时FR23=FR32=464.2788 N;FR4=FR4’=-444.5727 N;FR12x=-30.6418 N;FR12y=489.9903 N ;FR41x=-30.6418 N;FR41y=489.9903 N;Mb=-35.5658 N*m。
接下来取Φ1=0~360°范围分析其受力: h1=0.120; h2=0.08; W1=10; G2=40; G3=100; Fr=400;
18
th1=linspace(0,2*pi,36); x=zeros(length(th1),8); for n=1:36
x(n,:)=[lAB h1 h2 W1 G2 G3 Fr th1(n)]; end
p=zeros(8,length(th1)); for k=1:36
p(:,k)=F(x(k,:)); end >> p p =
Columns 1 through 8
400.0000 382.1443 364.8625 348.7101 334.2061 321.8169 311.9404 304.8943 500.0000 470.0039 426.9963 374.1872 314.6014 250.8119 184.7735 117.7719 500.0000 470.0039 426.9963 374.1872 314.6014 250.8119 184.7735 117.7719 40.0000 39.3572 37.4494 34.3380 30.1229 24.9396 18.9547 12.3607 400.0000 375.0020 350.8075 328.1941 307.8886 290.5436 276.7166 266.8521 40.0000 39.3572 37.4494 34.3380 30.1229 24.9396 18.9547 12.3607 400.0000 375.0020 350.8075 328.1941 307.8886 290.5436 276.7166 266.8521 40.0000 37.6003 34.1597 29.9350 25.1681 20.0650 14.7819 9.4218
Columns 9 through 16
300.9050 300.1007 302.5072 308.0472 316.5427 327.7205 341.2215 356.6116 50.4893 -16.8300 -84.1427 -151.3378 -217.9780 -283.0943 -345.0675 -401.6200 50.4893 -16.8300 -84.1427 -151.3378 -217.9780 -283.0943 -345.0675 -401.6200 5.3693 -1.7946 -8.9008 -15.7210 -22.0359 -27.6425 -32.3607 -36.0388
261.2670 260.1410 263.5101 271.2661 283.1597 298.8087 317.7101 339.2563 5.3693 -1.7946 -8.9008 -15.7210 -22.0359 -27.6425 -32.3607 -36.0388
261.2670 260.1410 263.5101 271.2661 283.1597 298.8087 317.7101 339.2563 4.0391 -1.3464 -6.7314 -12.1070 -17.4382 -22.6475 -27.6054 -32.1296
Columns 17 through 24
373.3963 391.0361 408.9639 426.6037 443.3884 458.7785 472.2795 483.4573 -449.9252 -486.8273 -509.1470 -514.0376 -499.3489 -463.9495 -407.9684 -332.9190 -449.9252 -486.8273 -509.1470 -514.0376 -499.3489 -463.9495 -407.9684 -332.9190 -38.5585 -39.8390 -39.8390 -38.5585 -36.0388 -32.3607 -27.6425 -22.0359 362.7548 387.4505 412.5495 437.2452 460.7437 482.2899 501.1913 516.8403 -38.5585 -39.8390 -39.8390 -38.5585 -36.0388 -32.3607 -27.6425 -22.0359 362.7548 387.4505 412.5495 437.2452 460.7437 482.2899 501.1913 516.8403 -35.9940 -38.9462 -40.7318 -41.1230 -39.9479 -37.1160 -32.6375 -26.6335
Columns 25 through 32
491.9528 497.4928 499.8993 499.0950 495.1057 488.0596 478.1831 465.7939
19
-241.6872 -138.3782 -28.0349 83.7439 191.2451 289.0952 372.6779 438.4701 -241.6872 -138.3782 -28.0349 83.7439 191.2451 289.0952 372.6779 438.4701 -15.7210 -8.9008 -1.7946 5.3693 12.3607 18.9547 24.9396 30.1229 528.7339 536.4899 539.8590 538.7330 533.1479 523.2834 509.4564 492.1114 -15.7210 -8.9008 -1.7946 5.3693 12.3607 18.9547 24.9396 30.1229 528.7339 536.4899 539.8590 538.7330 533.1479 523.2834 509.4564 492.1114 -19.3350 -11.0703 -2.2428 6.6995 15.2996 23.1276 29.8142 35.0776
Columns 33 through 36
451.2899 435.1375 417.8557 400.0000 484.2616 509.2386 513.9257 500.0000 484.2616 509.2386 513.9257 500.0000 34.3380 37.4494 39.3572 40.0000 471.8059 449.1925 424.9980 400.0000 34.3380 37.4494 39.3572 40.0000 471.8059 449.1925 424.9980 400.0000 38.7409 40.7391 41.1141 40.0000
P矩阵的每一行分别是八个未知量在Φ1等于36个分量下的值。整理表格如下:
表一 Φ1 FR23/FR32 FR4 FR4’ FR12X FR12Y FR41X FR41Y Mb rad N N N N N N N N*m 20
百度搜索“70edu”或“70教育网”即可找到本站免费阅读全部范文。收藏本站方便下次阅读,70教育网,提供经典综合文库地大机械原理大作业 - 图文(4)在线全文阅读。
相关推荐: