----- 截面特性 -----
主管截面:
A =6.5659e-003; ix =7.3977e-002; iy =7.3977e-002;
支管1截面:
A =2.8400e-003; ix =4.0052e-002; iy =4.0052e-002;
支管2截面:
A =2.8400e-003; ix =4.0052e-002; iy =4.0052e-002;
支管3截面:
A =2.8400e-003; ix =4.0052e-002; iy =4.0052e-002;
支管4截面:
A =2.8400e-003; ix =4.0052e-002; iy =4.0052e-002;