材料力学大作业组合截面几何性质计算.docx
材料力学大作业组合截面几何性质计算Harbin Institute of Technology 材料力学电算大作业 课程名称： 材料力学 设计题目： 组合截面几何性质计算 作者院系： 作者班级： 作者姓名： 作者学号： 指导教师： 完成时间： 一、 软件主要功能 圆形截面 圆环形截面 矩形截面 个数 n1 n2 n3 形心位置X X1(n1) X2(n2) X3(n3) 形心位置Y Y1(n1) Y2(n2) Y3(n3) 尺寸大小 d1(n1) d2(n2),d3(n2) h(n3),d(n3) S1,S2,S3分别是n1个圆形截面，n2个圆环形截面，n3个矩形截面的面积 X4，X5，X6分别是n1个圆形截面，n2个圆环形截面，n3个矩形截面的形心位置X与面积的乘积 Y4，Y5，Y6分别是n1个圆形截面，n2个圆环形截面，n3个矩形截面的形心位置Y与面积的乘积 Xc,Yc是总截面的形心坐标 Ix1,Ix2,Ix3分别是n1个圆形截面，n2个圆环形截面，n3个矩形截面对通过形心且与x轴平行的轴的惯性矩 Iy1,Iy2,Iy3分别是n1个圆形截面，n2个圆环形截面，n3个矩形截面对通过形心且与y轴平行的轴的惯性矩 Ixy1,Ixy2,Ixy3分别是n1个圆形截面，n2个圆环形截面，n3个矩形截面对通过形心且与x,y轴平行的两轴的惯性积 a是通过形心的主轴与x轴的夹角 Imax,Imin分别是截面对形心主轴的主惯性矩 软件截图： 二、 程序源代码 Dim n1 As Double Dim d1(10) As Double Dim X1(10) As Double Dim Y1(10) As Double Dim n2 As Double Dim d2(10) As Double Dim d3(10) As Double Dim X2(10) As Double Dim Y2(10) As Double Dim n3 As Double Dim h(10) As Double Dim d(10) As Double Dim X3(10) As Double Dim Y3(10) As Double Dim S1 As Double, S2 As Double, S3 As Double Dim X4 As Double, Y4 As Double, X5 As Double, Y5 As Double, X6 As Double, Y6 As Double Dim Xc As Double, Yc As Double Dim Ix1 As Double, Iy1 As Double, Ix2 As Double, Iy2 As Double, Ix3 As Double, Iy3 As Double, Imax As Double, Imin As Double Dim Ixy1 As Double, Ixy2 As Double, Ixy3 As Double Dim a As Double Private Sub Text1_Change n1 = Val(Text1.Text) For i = 1 To n1 d1(i) = Val(InputBox("输入第" & (i) & "个圆的直径") X1(i) = Val(InputBox("输入第" & (i) & "个圆的圆心的x坐标值") Y1(i) = Val(InputBox("输入第" & (i) & "个圆的圆心的y坐标值") Next i For i = 1 To n1 S1 = S1 + 3.14159 * d1(i) * d1(i) / 4 X4 = X4 + X1(i) * 3.14159 * d1(i) * d1(i) / 4 Y4 = Y4 + Y1(i) * 3.14159 * d1(i) * d1(i) / 4 Next i End Sub Private Sub Text2_Change n2 = Val(Text2.Text) For i = 1 To n2 d2(i) = Val(InputBox("输入第" & (i) & "个圆环的外径") d3(i) = Val(InputBox("输入第" & (i) & "个圆环的内径") X2(i) = Val(InputBox("输入第" & (i) & "个圆的圆心的x坐标值") Y2(i) = Val(InputBox("输入第" & (i) & "个圆的圆心的y坐标值") Next i For i = 1 To n2 S2 = S2 + 3.14159 * (d2(i) * d2(i) - d3(i) * d3(i) / 4 X5 = X5 + X2(i) * 3.14159 * (d2(i) * d2(i) - d3(i) * d3(i) / 4 Y5 = Y5 + Y2(i) * 3.14159 * (d2(i) * d2(i) - d3(i) * d3(i) / 4 Next i End Sub Private Sub Text3_Change n3 = Val(Text3.Text) For i = 1 To n3 h(i) = Val(InputBox("输入第" & (i) & "个矩形的高") d(i) = Val(InputBox("输入第" & (i) & "个矩形的宽") X3(i) = Val(InputBox("输入第" & (i) & "个矩形形心的x坐标值") Y3(i) = Val(InputBox("输入第" & (i) & "个矩形形心的y坐标值") Next i For i = 1 To n3 S3 = S3 + h(i) * d(i) X6 = X6 + X3(i) * h(i) * d(i) Y6 = Y6 + Y3(i) * h(i) * d(i) Next i End Sub Private Sub Command1_Click Xc = (X4 + X5 + X6) / (S1 + S2 + S3) Yc = (Y4 + Y5 + Y6) / (S1 + S2 + S3) Text4 = Xc Text5 = Yc End Sub Private Sub Command2_Click Picture1.BackColor = vbWhite Picture1.Scale (-Max - 10, Max + 10)-(Max + 10, -Max - 10) Picture1.Line (0, Max + 10)-(0, -Max - 10) Picture1.Line (Max + 10, 0)-(-Max - 10, 0) Picture1.FillStyle = 0 For i = 1 To n1 Step 1 Picture1.FillColor = vbBlue Picture1.Circle (X1(i), Y1(i), d1(i) / 2, vbRed Next i For i = 1 To n2 Step 1 Picture1.FillColor = vbGreen Picture1.Circle (X2(i), Y2(i), d2(i) / 2, vbRed Picture1.FillColor = vbWhite Picture1.Circle (X2(i), Y2(i), d3(i) / 2, vbRed Next i For i = 1 To n3 Step 1 Picture1.FillColor = vbRed Picture1.Line (X3(i) - d(i) / 2, Y3(i) - h(i) / 2)-(X3(i) + d(i) / 2, Y3(i) + h(i) / 2), vbRed, BF Next i End Sub Private Sub Command3_Click For i = 1 To n1 Ix1 = Ix1 + 3.14159 * d1(i) * d1(i) * d1(i) * d1(i) / 64 + (Y1(i) - Yc) * (Y1(i) - Yc) * 3.14159 * d1(i) * d1(i) / 4 Iy1 = Iy1 + 3.14159 * d1(i) * d1(i) * d1(i) * d1(i) / 64 + (X1(i) - Xc) * (X1(i) - Xc) * 3.14159 * d1(i) * d1(i) / 4 Ixy1 = Ixy1 + (X1(i) - Xc) * (Y1(i) - Yc) * 3.14159 * d1(i) * d1(i) / 4 Next i For i = 1 To n2 Ix2 = Ix2 + 3.14159 * (d2(i) * d2(i) * d2(i) * d2(i) - d3(i) * d3(i) * d3(i) * d3(i) / 64 + (Y2(i) - Yc) * (Y2(i) - Yc) * 3.14159 * (d2(i) * d2(i) - d3(i) * d3(i) / 4 Iy2 = Iy2 + 3.14159 * (d2(i) * d2(i) * d2(i) * d2(i) - d3(i) * d3(i) * d3(i) * d3(i) / 64 + (X2(i) - Xc) * (X2(i) - Xc) * 3.14159 * (d2(i) * d2(i) - d3(i) * d3(i) / 4 Ixy2 = Ixy2 + (X2(i) - Xc) * (Y2(i) - Yc) * 3.14159 * (d2(i) * d2(i) - d3(i) * d3(i) / 4 Next i For i = 1 To n3 Ix3 = Ix3 + h(i) * h(i) * h(i) * d(i) / 12 + (Y3(i) - Yc) * (Y3(i) - Yc) * h(i) * d(i) Iy3 = Iy3 + d(i) * d(i) * d(i) * h(i) / 12 + (X3(i) - Xc) * (X3(i) - Xc) * h(i) * d(i) Ixy3 = Ixy3 + (X3(i) - Xc) * (Y3(i) - Yc) * h(i) * d(i) Next i Imax = (Ix1 + Ix2 + Ix3 + Iy1 + Iy2 + Iy3) / 2 + Sqr(Ix1 + Ix2 + Ix3 - Iy1 - Iy2 - Iy3) * (Ix1 + Ix2 + Ix3 - Iy1 - Iy2 - Iy3) / 4 + (Ixy1 + Ixy2 + Ixy3) * (Ixy1 + Ixy2 + Ixy3) Imin = (Ix1 + Ix2 + Ix3 + Iy1 + Iy2 + Iy3) / 2 - Sqr(Ix1 + Ix2 + Ix3 - Iy1 - Iy2 - Iy3) * (Ix1 + Ix2 + Ix3 - Iy1 - Iy2 - Iy3) / 4 + (Ixy1 + Ixy2 + Ixy3) * (Ixy1 + Ixy2 + Ixy3) Text6 = Imax Text7 = Imin If Ix <> Iy Then a = Math.Atn(-2 * (Ixy1 + Ixy2 + Ixy3) / (Ix1 + Ix2 + Ix3 - Iy1 - Iy2 - Iy3) / 2 Picture1.Line (Xc, Yc)-(Xc + 20, Yc + 20 * Tan(a), vbGreen Picture1.Line (Xc, Yc)-(Xc - 20 * Tan(a), Yc + 20), vbGreen Else Picture1.Line (Xc, Yc)-(Xc, Yc + 20), vbGreen Picture1.Line (Xc, Yc)-(Xc + 20, Yc), vbGreen End If End Sub 程序见 三、 例题的计算结果数据 已知一工字型钢如图所示上下两矩形一样，宽是1，高是0.4，中间的矩形宽是0.4，高是2 求形心及主惯性矩 解： Xc=0.5 Yc=1.4 Ix1= 0.58 Iy1=0.0333 Ix2= 0.267 Iy2=0.0107 Ix3= 0.58 Iy3=0.0333 Ixy1= Ixy2= Ixy3=0 夹角a=0° Ix总= Ix1+ Ix2+ Ix3=1.427 Iy总= Iy1+ Iy2+ Iy3=0.0773 Imax=1.427 Imin=0.0773 计算结果如图：
