1板梁单元质量刚度矩阵（公式）

说明：  39节点系统稳态和暂态运算的bpa源代码(BPA power flow calculation code for 39-node system)

说明：  可以用该程序进行多自由度结构的地震控制计算(Earthquake control calculation of structures)

说明：  黄河流域二级支流shp文件，已经修正过的，做底图很好用的。(Shp files of secondary tributaries in the Yellow River Basin)

说明：  ansys命令流，计算由于振动引起的高层建筑物的表面振动加速度，不过激励是施加在土体上的(ANSYS command flow is used to calculate the surface vibration acceleration of high-rise buildings caused by vibration, but the excitation is applied to the soil)

说明：  滞回环面积求解，实验数据中滞回曲线的面积计算，采用MATLAB编写。(Solving the area of hysteresis loop)

说明：  采用初始应力法进行被动土压力分析，程序中对相关矩阵及每一步的意义进行了简要说明(The code uses the initial stress method to analyze the passive earth pressure. The relevant matrix and the significance of each step are briefly explained in the program.)

说明：  此程序为本人自行编制的矩形移动荷载作用下饱和土地基的动应力响应问题的MATLAB程序，适合相关研究方向的初学者。(This program is a matlab program for the dynamic stress response of saturated soil foundation under the action of rectangular moving load, which is suitable for beginners in related research fields.)

精细积分法Matlab程序，利用该程序对动力系统的微分方程精细求解。(The program of precise integration method MATLAB is used to solve the differential equation of dynamic system precisely.)

说明：  使用有限元方法，可以直接求解加筋板结构的质量刚度矩阵(Using the finite element method, the mass stiffness matrix of stiffened plate structure can be solved directly)

diff 2 for stationary data