哈工大机械原理大作业一连杆-15题 - 图文

VXC=-w*LAB*cos(wt)– (Lbc2?Lab2*sin2wt)-1/2 * sin(wt)*w

VYC = 0

加速度分析：

将上式分别对时间求导，可得加速度方程, （3）RPR Ⅱ级基本杆组

位置分析： XD = XC+ LCD * cosβ

YD = - LCD * sinβ

可求得， θ = arctan (-YD / (LAE-XD) ) 速度分析：

将上式分别对时间求导，可得速度方程,

5．计算编程

在MATLAB中编写如下程序：

function [ XD,YD,Q,Q1,Q2] = calculate(t) %UNTITLED4 Summary of this function goes here % Detailed explanation goes here Lab=100; Lbc=200; Lcd=200; Lae=400; w=10;

XB=Lab*cos(w.*t); YB=Lab*sin(w.*t); P=asin(YB./Lbc); XC=sqrt(Lbc.^2-YB.^2)+XB; XD=Lcd.*cos(P)+XC; YD=-Lcd.*sin(P); Q=atan(YD./(Lae-XD)); Q1=diff(Q); Q2=diff(Q1); end

5．计算结果 t 时间 0 XD D点横坐标 500 YD D点纵坐标 0 Q 构件5角度 0 Q1 Q2 构件5角速度 构件5角加速度 0.1005 0.003008 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 0.11 0.12 0.13 0.14 0.15 0.16 0.17 0.18 0.19 0.2 0.21 0.22 0.23 0.24 0.25 0.26 0.27 0.28 0.29 0.3 0.31 0.32 0.33 0.34 0.35 0.36 0.37 0.38 0.39 0.4 0.41 0.42 0.43 499.0018 496.0283 491.1429 484.4505 476.0958 466.2615 455.1653 443.0552 430.2044 416.9036 403.4517 390.1455 377.267 365.0708 353.7727 343.5394 334.4828 326.6576 320.0638 314.6537 310.3405 307.0096 304.5286 302.7576 301.5573 300.7957 300.3534 300.127 300.0319 300.0038 300 300.0001 300.0059 300.0417 300.1538 300.4101 300.8984 301.725 303.0118 304.8923 307.5065 310.9937 315.4839 -9.98334 -19.8669 -29.552 -38.9418 -47.9426 -56.4642 -64.4218 -71.7356 -78.3327 -84.1471 -89.1207 -93.2039 -96.3558 -98.545 -99.7495 -99.9574 -99.1665 -97.3848 -94.63 -90.9297 -86.3209 -80.8496 -74.5705 -67.5463 -59.8472 -51.5501 -42.738 -33.4988 -23.9249 -14.112 -4.15807 5.837414 15.77457 25.55411 35.07832 44.25204 52.98361 61.18579 68.77662 75.68025 81.82771 87.15758 91.61659 0.1005 0.204008 0.313543 0.432063 0.562207 0.705736 0.862648 1.030235 1.202772 1.372554 1.532085 -1.46546 -1.33911 -1.23016 -1.13683 -1.05663 -0.98695 -0.9253 -0.86937 -0.81706 -0.76643 -0.71567 -0.6631 -0.6071 -0.54624 -0.47923 -0.40517 -0.32362 -0.23491 -0.1402 -0.04156 0.058308 0.156466 0.250287 0.337854 0.418139 0.490973 0.55687 0.616823 0.672133 0.72429 0.774904 0.825689 0.103508 0.109535 0.11852 0.130145 0.143529 0.156912 0.167587 0.172537 0.169781 0.159531 -2.99754 0.126353 0.108942 0.093336 0.080201 0.069675 0.06165 0.055928 0.052312 0.050632 0.050757 0.052577 0.055991 0.060868 0.067004 0.074067 0.081544 0.088715 0.094708 0.098643 0.099865 0.098157 0.093821 0.087567 0.080286 0.072834 0.065896 0.059953 0.05531 0.052157 0.050614 0.050785 0.05278 0.006027 0.008986 0.011624 0.013384 0.013383 0.010676 0.00495 -0.00276 -0.01025 -3.15707 3.123895 -0.01741 -0.01561 -0.01314 -0.01053 -0.00803 -0.00572 -0.00362 -0.00168 0.000124 0.00182 0.003414 0.004877 0.006136 0.007063 0.007476 0.007171 0.005993 0.003935 0.001222 -0.00171 -0.00434 -0.00625 -0.00728 -0.00745 -0.00694 -0.00594 -0.00464 -0.00315 -0.00154 0.000171 0.001995 0.003957 0.44 0.45 0.46 0.47 0.48 0.49 0.5 0.51 0.52 0.53 0.54 0.55 0.56 0.57 0.58 0.59 0.6

D点运动轨迹：

321.0879 327.8866 335.9204 345.1802 355.6018 367.064 379.3912 392.3604 405.7114 419.1588 432.4048 445.151 457.1091 468.0097 477.6095 485.6965 492.0941 95.16021 97.75301 99.3691 99.99233 99.61646 98.24526 95.89243 92.58147 88.34547 83.22674 77.27645 70.55403 63.12666 55.06855 46.46022 37.38767 27.94155 0.87847 0.935207 0.998039 1.069305 1.151531 1.247329 1.359101 1.488466 -1.50624 -1.34454 -1.17373 -1.00152 -0.8354 -0.68064 -0.53942 -0.41139 -0.29457 0.056738 0.062832 0.071266 0.082226 0.095797 0.111772 0.129365 -2.9947 0.1617 0.170805 0.172214 0.166115 0.154767 0.141218 0.128033 0.116811 0.108311 0.006095 0.008433 0.010961 0.013571 0.015975 0.017592 -3.12407 3.156403 0.009105 0.001409 -0.0061 -0.01135 -0.01355 -0.01318 -0.01122 -0.0085 -0.00552

构件5的角位移线图：

构件5的角速度图：

构件5的角加速度线图：

6．计算结果分析

原动件1可做整周回转，同时构件5也可做整周运动。构件5的角位移线图有较大波动，且出现尖点，而角速度线图有明显的阶跃现象，说明构件5有显著的急回特性。而构件角加速度为在一个周期内发生两次突变，可产生较大冲击力。总之，从角速度和角加速度变化规律大致可以看出包含了更高阶的正余弦谐波分量。