1、tanddxwxwdd1EIM-dxd22边界条件:连续性条件:xl/4,w1w2 xl/4,1=2 1P3044lMxF xx 2PP3444llMxF xFxxl 211P2d30d44wlEIMxF xxx 1P3044lMxF xx 2PP3444llMxF xFxxl 222PP2d3d444wllEIMxF xFxxlx 211P2d30d44wlEIMxF xxx 222PP2d3d444wllEIMxF xFxxlx12P183CxFEI22P2P242183ClxFxFEI113P181DxCxFEIw223P3P246181DxClxFxFEIw12P183CxFEI22P
2、2P242183ClxFxFEI113P181DxCxFEIw223P3P246181DxClxFxFEIwx0,w10;xl,w20 xl/4,w1w2;xl/4,1=212P183CxFEI22P2P242183ClxFxFEI113P181DxCxFEIw223P3P246181DxClxFxFEIwx0,w10;xl,w20 xl/4,w1w2;xl/4,1=2D1D2=02P211287lFCC 22P378128FxxlEI xlxEIFxw23P128781 222P317824128FlxxxlEI xllxxEIFxw233P128746181EIlFwB3P25632P71
3、28AF lEIEIlF1285-3pC 确定约束力,判断是否需要分段以及分几段 分段建立挠度微分方程 微分方程的积分 利用约束条件和连续条件确定积分常数 确定挠度与转角方程以及指定截面的挠度与转角 分段写出弯矩方程321CCCCwwww123BBBBEIqlwEIqlwEIqlwCCC4342411614813845,EIqlEIqlEIqlBBB33323131161241,EIqlwwiCiC43138411EIqliBiB3314811414322218112128482,CCBBqlwEIlqlqllwwEIEI EIqlEIqlCC323148161,EIqlwwiCiC42138
4、441EIqliCiC321487 maxB例:例:BEIlaFB3P BB0.518064d1020631011021020-1803EIlaF-3333PB4mm111d 若跨度缩短若跨度缩短10%,最大,最大挠度减小挠度减小34.4%三者比值:三者比值:128:8:1最大挠度是集中载最大挠度是集中载荷的荷的37.5%3-3=04-3=1lMA ABFAyFAxql ABMAFAyFAxFB532633FBxMBBl AMAFAyFAxFByBl AMAFAyFAxFBxFByFBxBl AMAFAyFAxFBy 应用对称性分析可以推知某些未知量MBBl AMAFAyFAxFBxFByMBBl AMA作业:134 13-8