2.19分析如图所示体系的几何组成。
解：结点,1,0,0结点,2,10,0结点,3,20,0结点,4,5,-5结点,5,15,-5结点,6,10,-10单元,1,2,1,1,0,1,1,0单元,2,3,1,1,0,1,1,0单元,3,5,1,1,0,1,1,0单元,5,6,1,1,0,1,1,0单元,6,4,1,1,0,1,1,0单元,4,1,1,1,0,1,1,0单元,4,2,1,1,0,1,1,0单元,2,5,1,1,0,1,1,0结点支承,1,2,-90,0,0结点支承,6,2,0,0,0结点支承,3,1,0,0位移模型：静态显示解答:有2个多余约束，体系自由度为1，的几何瞬变体系。
3.25计算静定多跨梁的支座反力，并画出梁的内力图。
解：结点,1,0,0结点,2,6,0结点,3,7.5,0结点,4,12,0结点,5,14,0结点,6,18,0单元,1,2,1,1,0,1,1,1单元,2,3,1,1,1,1,1,0单元,3,4,1,1,0,1,1,1单元,4,5,1,1,1,1,1,0单元,5,6,1,1,0,1,1,0结点支承,1,2,-90,0,0结点支承,2,1,0,0结点支承,4,1,0,0结点支承,6,1,0,0单元荷载,1,1,20,1/2,90单元荷载,3,1,10,1/2,90单元荷载,4,3,2,0,1,90单元荷载,5,3,2,0,1,90尺寸线,1,0.5,0.5,7.8,1.0,0.5,0,-3,3m,3,-3,3m,6,-3尺寸线,1,0.5,0.5,7.8,0.5,0.5,6,-3,1.5m,7.5,-3,2m,9.5,-3,2.5m,12,-3,2m,14,-3 尺寸线,1,0.5,0.5,7.8,1,0.5,14,-3,4m,18,-3解答：弯矩图剪力图轴力图4.14计算E上各杆端截面内力。
解：结点,1,0,0结点,2,4,0结点,3,8,0结点,4,0,3结点,5,4,3结点,6,8,3单元,1,4,1,1,0,1,1,1单元,4,5,1,1,1,1,1,1单元,5,6,1,1,1,1,1,1单元,6,3,1,1,1,1,1,0单元,5,2,1,1,1,1,1,0结点支承,1,1,0,0结点支承,2,1,90,0结点支承,3,1,0,0单元荷载,2,1,8,1/2,90单元荷载,3,1,8,1/2,90单元荷载,1,3,3,0,1,90尺寸线,1,0.2,0.1,7.8,1.0,0.5,0,-1.5,2m,2.0,-1.5,2m,4,-1.5,2m,6,-1.5,2m,8,-1.5 尺寸线,1,0.2,0.1,7.8,1.0,0.5,9.5,0,3m,9.5,3解答：8.5作C截面内力影响线。
解：结点,1,0,0结点,2,2,0结点,3,4,0结点,4,6,0结点,5,6,0.5结点,6,4,0.5结点,7,2,0.5结点,8,0,0.5单元,1,2,1,1,0,1,1,1单元,2,3,1,1,1,1,1,1单元,3,4,1,1,1,1,1,0单元,4,5,1,1,0,1,1,0单元,5,6,1,1,0,1,1,0单元,6,7,1,1,0,1,1,0单元,7,8,1,1,0,1,1,0单元,8,1,1,1,0,1,1,0单元,7,2,1,1,0,1,1,0单元,6,3,1,1,0,1,1,0结点支承,1,2,-90,0,0结点支承,4,1,0,0影响线参数,-2,1,1/2,3影响线参数,-2,1,1/2,2尺寸线,1,0.2,0.1,7.8,1,0.5,0,-1,1m,1,-1,1m,2,-1,2m,4,-1,2m,6,-1文本,1,-0.3,C,0,0,7.8Mc上乘时影响线Mc下乘时影响线9.22求C点挠度。
已知p=9kn,q=15kn/m,梁为18号工字钢，I=1660cm^4,h=18cm,E=2.1*10^8kpa。
解：结点,1,0,0结点,2,3,0结点,3,1.5,0结点,4,-0.9,0单元,4,1,1,1,1,1,1,1单元,1,3,1,1,1,1,1,1单元,3,2,1,1,1,1,1,0结点支承,1,3,0,0,0结点支承,2,1,0,0单元荷载,3,3,15,0,1,90单元荷载,2,3,15,0,1,90结点荷载,4,1,9,-90单元材料性质,1,3,642600,3486,0,0,-1解答：C点挠度，0.00323123m,竖直向下12.22用剪力分配法作图示刚架弯矩图（分别计算横梁为刚性和弹性两种情况，进行比较）。
解：（1），横梁弹性结点,1,0,0结点,2,4,0结点,3,10,0结点,4,0,5结点,5,4,5结点,6,10,5结点,7,0,10结点,8,4,10结点,9,10,10单元,1,4,1,1,1,1,1,1单元,4,5,1,1,1,1,1,1单元,5,6,1,1,1,1,1,1单元,6,9,1,1,1,1,1,1单元,9,8,1,1,1,1,1,1单元,8,7,1,1,1,1,1,1单元,7,4,1,1,1,1,1,1单元,2,5,1,1,1,1,1,1单元,5,8,1,1,1,1,1,1单元,6,3,1,1,1,1,1,1结点支承,1,6,0,0,0,0结点支承,2,6,0,0,0,0结点支承,3,6,0,0,0,0结点荷载,4,1,100,0结点荷载,7,1,50,0尺寸线,1,0.2,0.1,7.8,1.0,0.5,0,-1.5,4m,4,-1.5,6m,10,-1.5尺寸线,1,0.2,0.1,7.8,1.0,0.5,12,0,5m,12,5,5m,12,10单元材料性质,1,1,-1,10,0,0,-1单元材料性质,8,8,-1,10,0,0,-1单元材料性质,10,10,-1,10,0,0,-1单元材料性质,2,2,-1,28,0,0,-1单元材料性质,3,3,-1,60,0,0,-1单元材料性质,7,7,-1,5,0,0,-1单元材料性质,9,9,-1,5,0,0,-1单元材料性质,4,4,-1,5,0,0,-1单元材料性质,6,6,-1,16,0,0,-1单元材料性质,5,5,-1,30,0,0,-1横梁弹性时，弯矩图（2）横梁刚性结点,1,0,0结点,2,4,0结点,3,10,0结点,4,0,5结点,5,4,5结点,6,10,5结点,7,0,10结点,8,4,10结点,9,10,10单元,1,4,1,1,1,1,1,1单元,4,5,1,1,1,1,1,1单元,5,6,1,1,1,1,1,1单元,6,9,1,1,1,1,1,1单元,9,8,1,1,1,1,1,1单元,8,7,1,1,1,1,1,1单元,7,4,1,1,1,1,1,1单元,2,5,1,1,1,1,1,1单元,5,8,1,1,1,1,1,1单元,6,3,1,1,1,1,1,1结点支承,1,6,0,0,0,0结点支承,2,6,0,0,0,0结点支承,3,6,0,0,0,0结点荷载,4,1,100,0结点荷载,7,1,50,0尺寸线,1,0.2,0.1,7.8,1.0,0.5,0,-1.5,4m,4,-1.5,6m,10,-1.5尺寸线,1,0.2,0.1,7.8,1.0,0.5,12,0,5m,12,5,5m,12,10单元材料性质,1,1,-1,10,0,0,-1单元材料性质,8,8,-1,10,0,0,-1单元材料性质,10,10,-1,10,0,0,-1单元材料性质,7,7,-1,5,0,0,-1单元材料性质,9,9,-1,5,0,0,-1单元材料性质,4,4,-1,5,0,0,-1单元材料性质,2,2,-1,-1,0,0,-1单元材料性质,3,3,-1,-1,0,0,-1单元材料性质,5,5,-1,-1,0,0,-1单元材料性质,6,6,-1,-1,0,0,-1横梁刚性时，弯矩图17.3求图示梁的极限荷载。
解：结点,1,0,0结点,2,4,0结点,3,6,0结点,4,7,0单元,1,2,1,1,1,1,1,0单元,2,3,1,1,0,1,1,1单元,3,4,1,1,1,1,1,1结点支承,1,6,-90,0,0,0结点支承,3,1,0,0结点荷载,4,1,1,-90单元材料性质,1,1,0,0,0,1.5,-1单元材料性质,2,3,0,0,0,1,-1尺寸线,1,0.2,0.1,7.8,1.0,0.5,0,-1,4m,4,-1,2m,6,-1,1m,7,-1破坏机构静态显示解答：15.3求图示体系的自振频率。
解：结点,1,0,0结点,2,1,0结点,3,1,0.5单元,1,2,1,1,0,1,1,1单元,2,3,1,1,1,1,1,1结点支承,1,3,0,0,0结点支承,2,1,0,0集中质量,3,3,1单元材料性质,1,1,-1,1,0,0,-1单元材料性质,2,2,-1,-1,0,0,-1自振频率参数,2,1,0.0005尺寸线,1,0.02,0.02,7.8,1,0.5,0,-0.2,l,1,-0.2尺寸线,1,0.02,0.02,7.8,1,0.5,1.2,0,h,1.2,0.5解答：（1）第一阶频率：3.46411923518839静态振型（2）第二阶频率：141421。
356168082静态振型。