📄 3084.htm
字号:
<HTML><HEAD><TITLE>new</TITLE><META content="text/html; charset=gb2312" http-equiv=Content-Type><LINK href="text.css" rel=stylesheet type=text/css><META content="Microsoft FrontPage 4.0" name=GENERATOR></HEAD><body leftmargin="15"><center><b><br>4 （无阻尼）自由振动</b></center> <table border="0" cellpadding="0" cellspacing="0" width="560"> <tr> <td> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tr> <td width="50%"><b><font color="#0000FF">一、模型</font></b></td> <td width="25%" rowspan="5"> <p align="center"><img border="0" src="pic2/3084.h59.gif" width="176" height="103"></td> <td width="25%" rowspan="5"> <p align="center"><img border="0" src="pic2/3084.h60.gif" width="109" height="130"></td> </tr> <tr> <td width="50%">两种最简模型如图。</td> </tr> <tr> <td width="50%">对扭转振动：</td> </tr> <tr> <td width="50%"><img border="0" src="pic2/3084.h61.gif" width="108" height="28"></td> </tr> <tr> <td width="50%">Kn -------扭转刚度</td> </tr> <tr> <td width="50%"></td> <td width="25%" align="center">直线振动</td> <td width="25%" align="center">扭转振动</td> </tr> </table> </td> </tr> <tr> <td><b><font color="#0000FF">二、振动方程</font></b></td> </tr> <tr> <td> <table border="0" cellpadding="0" cellspacing="0"> <tr> <td><img border="0" src="pic2/3084.h62.gif" width="89" height="22"></td> <td> 或 </td> <td><img border="0" src="pic2/3084.h63.gif" width="91" height="31"></td> <td></td> <td> （1）</td> </tr> </table> </td> </tr> <tr> <td> <table border="0" cellpadding="0" cellspacing="0"> <tr> <td>式中 <b>（无阻尼）固有（圆）频率</b></td> <td> <img border="0" src="pic2/3084.h64.gif" width="79" height="56"> </td> <td><b>固有周期 </b></td> <td><img border="0" src="pic2/3084.h65.gif" width="66" height="52"></td> <td></td> <td></td> </tr> <tr> <td> <p align="center"><b>固有频率 </b></td> <td><img border="0" src="pic2/3084.h66.gif" width="106" height="52"></td> <td></td> <td></td> <td></td> <td></td> </tr> </table> </td> </tr> <tr> <td><b><font color="#0000FF">三、解</font></b></td> </tr> <tr> <td>由常微分方程理论知方程(1)的解：</td> </tr> <tr> <td><img border="0" src="pic2/3084.h67.gif" width="227" height="87"></td> </tr> <tr> <td>式中A和θ为由初始条件确定的两个常数。</td> </tr> <tr> <td></td> </tr> <tr> <td> <p align="center"> <a href="3083.htm"><font color="#FF6666">[ 上一节 ]</font></a> <a href="3085.htm"><font color="#00CC00">[ 下一节 ]</font></a> </td> </tr> </table> </BODY></HTML> ⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -