目 录
第1章 绪 论 ................................................................................ 2 第2章 单跨梁的弯曲理论............................................................ 2 第3章 杆件的扭转理论............................................................ 15 第4章 力法 .............................................................................. 17 第5章 位移法 ............................................................................ 28 第6章 能量法 ............................................................................ 41 第7章 矩阵法 ............................................................................ 56 第9章 矩形板的弯曲理论.......................................................... 69 第10章 杆和板的稳定性............................................................ 75
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第1章 绪 论
1.1 题
1)承受总纵弯曲构件:
连续上甲板,船底板,甲板及船底纵骨,连续纵桁,龙骨等远离中
和轴的纵向连续构件(舷侧列板等)
2)承受横弯曲构件:甲板强横梁,船底肋板,肋骨
3)承受局部弯曲构件:甲板板,平台甲板,船底板,纵骨等
4)承受局部弯曲和总纵弯曲构件:甲板,船底板,纵骨,递纵桁,龙
骨等
1.2 题
甲板板:纵横力(总纵弯曲应力沿纵向,横向货物或上浪水压力,横向
作用)
舷侧外板:横向水压力等骨架限制力沿中面
内底板:主要承受横向力货物重量,骨架限制力沿中面为纵向力 舱壁板:主要为横向力如水,货压力也有中面力
第2章 单跨梁的弯曲理论
2.1题
设坐标原点在左跨时与在跨中时的挠曲线分别为v(x)与v(x1)
1)图2.1? v(x)?M0x2EI2?N?x36EI2?l43p(x?l)4?6EIl23p(x?l)2?6EI3l4p(x?3l)4 6EI3原点在跨中:v1(x1)?v0?M0x12EI?N?x16EI3?l43?v(l)?0v'(l)?0p(x?l)12?124,? p'6EI?v1(0)?0N1(0)??22)图2.2?v(x)??0x?Mx22EI?N?x36EIx0?l33p(x?l)3 6EI3p(x?l)2 6EI3)图2.3?v(xx)??0xx?N?x36EI??qxdx6EI3?l22.2题
a) v1?vpppl?1131?pl?1131??vp?(3???)??(?2?)? ???6EI?16444?6EI?41624?pl333 =
512EIpl3
V2?3?1?91?13?pl3pl???()???
6EI?4?192EI96EI4???162? 2
b) v(0)?'?Ml3EI?Ml6EI?2Pl296EI2(1?2)
32 =?0.1Pl6EI2?5Pl3?27EI2Pl2?73Pl1620EI
?(l)??Ml3EI?Ml6EI2?96EI2(1?1)
32 =?0.1Pl6EI?4Pl3?27EI22??107Pl1620EI
?l??2l?2p???l??3??3? vl??333EIl6EI??1???11?1????m2?3?m1?3?
3?????? =
37pl22430EI
4 c) vl3 ??2??192EI?768EI2304EIql3ql47ql5ql4 v(0)??'24EI??pl216EI???ql2166EI?l?ql11?ql3?1 ?????96EI8EI?3612?3d)2.1图、2.2图和2.3图的弯矩图与剪力图如图2.1、图2.2和图2.3
图2.1
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图2.2
图2.3
2.3题
1)
??右??M?Ml6EI13q1l?2ql324EI?Ml?l?q?q??0??21?45EI?23EI??
2l2120 2)?0??Ml3EI3?q1l324EI?Ml?l?lq? 1??180EI?2?6EI37l2ql?1q1l1713?????? =1?? ?EI?18243606?120?80EI2.4 题
图2.5 ?v(x)?v0??0x??N0x36EI,
v0?A?p?N0?
?x3??v(x)?Ap??0x???A?N0
?6EI? 4
如图2.4, 由v?l??v??l??0得
??l3?Ap??0l???A?N0?0?6EI????2l??0?N0?0?2EI?2?pl?Ap????0?l6EI??N?p3?0解出
33pl?3xx?3 ?v(x)??1?9EI?2l2l?? 图2.4 ? 图2.6
Mx2?v?x???1x?由v?l??0,M0l202EI?N0x6EI3v??l???2N0l3得4EI2EI?M?????201? ?ll??N?6EI?????122?0l?2??1l???0??2EI6EI?2M0lN0l?1????2??EI2EI??v?x???1x?l解得?2?1??2?x2???1??2?x3l2.5题
图2.5:(剪力弯矩图如2.5)
?R1?pl?Mll3??p??2p32p3??pl322p39EI33v0?AR?6EIMlplpl5pl?l?vv???0????216EI18EI48EI144EI?2?v??0???0??v0l?Ml6EI??pl2
9EI?pl218EI??pl26EIM?pa?bb? , 图2.5 A?1?l?KA?6l????将a?l,b?0A?l6,KA?16?13?12代入得:M?pl1???6312pl
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