機(jī)械原理大作業(yè)1

1/11機(jī)械原理大作業(yè)(一)作業(yè)名稱：連桿機(jī)構(gòu)運(yùn)動(dòng)分析設(shè)計(jì)題目：第八題 班級(jí)：設(shè)計(jì)者：學(xué)號(hào)：指導(dǎo)教師：明設(shè)計(jì)時(shí)間：2013年06月20日 工業(yè)大學(xué)機(jī)械設(shè)計(jì)2/11一、題目BCaACd試研究當(dāng)BC為主動(dòng)件時(shí)，a、d的長(zhǎng)度變化對(duì)從動(dòng)件的角位移、角速度和角加速度的影響規(guī)律C響規(guī)律。AadaC二、機(jī)構(gòu)的結(jié)構(gòu)分析機(jī)構(gòu)可分為兩部分 (2)、剛性桿三、各基本桿組的運(yùn)動(dòng)分析數(shù)學(xué)模型并建立直角坐標(biāo)系3/11 YAWt／n`adn／w`t`XC可推出從動(dòng)件的角位移n=arcsin(d*sin(w*t)/a)-w*t,，對(duì)其求導(dǎo)可得從動(dòng)件的角速度v=(d*t*cos(t*w))/(a*(1-(d^2*sin(t*w)^2)/a^2)^(1/2))–t，再對(duì)v求導(dǎo)得從動(dòng)件的角加速a1=(d^3*t^2*cos(t*w)^2*sin(t*w))/(a^3*(1-(d^2*sin(t*w)^2)/a^2)^(3/2))-(d*t^2*sin(t*w))/(a*(1-(d^2*sin(t*w)^2)/a^2)^(1/2))。從動(dòng)件的角位移n`=arctan(asin(w`*t`)/(d-a*cosw`*t`))，從動(dòng)件的角速度v`=(t`/((d-a*cos(t`*w`))*(1–t`^2*w`^2)^(1/2))-(a*t`*asin(t`*w`)*sin(t`*w`))/(d-a*cos(t`*w`))^2)/(asin(t`*w`)^2/(d-a*cos(t`*w`))^2+1)。從動(dòng)件的角加速度a1`=((t^3*w)/((d-a*cos(t*w))*(1-t^2*w^2)^(3/2))+(2*a^2*t^2*asin(t*w)*sin(t*w)^2)/(d-a*cos(t*w))^3-(a*t^2*asin(t*w)*cos(t*w))/(d-a*cos(t*w))^2-(2*a*t^2*sin(t*w))/((d-a*cos(t*w))^2*(1-t^2*w^2)^(1/2)))/(asin(t*w)^2/(d-a*cos(t*w))^2+1)-((t/((d-a*cos(t*w))*(1-t^2*w^2)^(1/2))-(a*t*asin(t*w)*sin(t*w))/(d-a*cos(t*w))^2)*((2*t*asin(t*w))/((d-a*cos(t*w))^2*(1-t^2*w^2)^(1/2))-(2*a*t*asin(t*w)^2*sin(t*w))/(d-a*cos(t*w))^3))/(asin(t*w)^2/(d-a*cos(t*w))^2五、計(jì)算編程4/11.forp=0.1:10:100mstsymsd;symsa;n=asin(sin(w*t)*d/a)-w*t;v=diff(n);a1=diff(v);t=0:pi/100:pi/5;y1=asin(sin(w*t)*d/a)-w*t;fori=1:length(t)y2(i)=subs(v,t(i));y3(i)=subs(a1,t(i));figure(p)plot(t,y1)同理修改程序?qū)⒈壤優(yōu)?.95、0.8、0.55/11.接著將其比例減小為0.2、0.1結(jié)果分析：由此可得，隨著d/a比例的不斷減小，但是通過(guò)常識(shí)可知當(dāng)a<d即d/a>1時(shí)AB為主動(dòng)件其角度不可能為0到2pi所以大于1的圖不存在，從小于1可以看出d/a不斷減小從動(dòng)件BC的角位移趨近于一次函數(shù)，即變化減緩。forp=1mstsymsd;symsa;n=asin(sin(w*t)*d/a)-w*t;v=diff(n);a1=diff(v);t=0:pi/100:pi/5;y1=asin(sin(w*t)*d/a)-w*t;fori=1:length(t)y2(i)=subs(v,t(i));y3(i)=subs(a1,t(i));figure(p)6/11.plot(t,y2)結(jié)果分析：由角速度曲線可知當(dāng)d/a的比例不斷減小時(shí)角速度趨向平穩(wěn)即最大值與最小值的差值減小，這也符合角位移趨向于一次曲線，峰值處的變化變的尖銳。另外通過(guò)角速度曲線可知0度時(shí)速度最大、180度時(shí)速度最小。mstsymsd;symsa;n=asin(sin(w*t)*d/a)-w*t;v=diff(n);a1=diff(v);t=0:pi/100:pi/5;7/11.y1=asin(sin(w*t)*d/a)-w*t;fori=1:length(t)y2(i)=subs(v,t(i));y3(i)=subs(a1,t(i));figure(p)plot(t,y3)結(jié)果分析：有圖可分析知隨著d/的a減小角加速度的幅值減小、在峰值處變化變得光滑，另2、BC為主動(dòng)件mstsymsd;symsa;8/11.n=atan(asin(w*t)/(d-a*cos(w*t)));v=diff(n);a1=diff(v);t=0:pi/100:pi/5;fori=1:length(t)y1(i)=subs(n,t(i));y2(i)=subs(v,t(i));y3(i)=subs(a1,t(i));figure(p)plot(t,y1)結(jié)果分析：由這幾個(gè)圖像課分析得在d/a<1時(shí)隨著d/a的增大角位移的突變減小，d/a=1無(wú)法運(yùn)動(dòng)，d/a>1時(shí)隨著d/a的增大角位移，角位移的變化幅度減小。forp=19/11.mstsymsd;symsa;n=atan(asin(w*t)/(d-a*cos(w*t)));v=diff(n);a1=diff(v);t=0:pi/100:pi/5;fori=1:length(t)y1(i)=subs(n,t(i));y2(i)=subs(v,t(i));y3(i)=subs(a1,t(i));figure(p)plot(t,y2)0/11.結(jié)果分析：由這幾圖可以看出在d/a<1時(shí)隨著d/a的增加，速度的幅值減小，d/a>1時(shí)隨著d/a的增加速度的幅值變化減小即從動(dòng)桿件的運(yùn)動(dòng)變得平穩(wěn)mstsymsd;symsa;n=atan(asin(w*t)/(d-a*cos(w*t)));v=diff(n);a1=diff(v);t=0:pi/100:pi/5;fori=1:length(t)y1(i)=subs(n,t(i));y2(i)=subs(v,t(i));y3(i)=subs(a1,t(i));figure(p)plot(t,y3).結(jié)果分析：由角加速度的隨d/的a變化圖可知在d/a<時(shí)1角加速度的幅值在一定圍變化減d/a不斷減小從動(dòng)件BC的角位移趨近于一次函數(shù)，即變化減緩。角速度變化曲