TAILIEUCHUNG - Applied Structural Mechanics Fundamentals of Elasticity Part 13

Tham khảo tài liệu 'applied structural mechanics fundamentals of elasticity part 13', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 346 15 Fundamentals of structural optimization 16 MP-algorithms For the bar stresses we formulate the following constraints E1 X -8ti x i x - tidm 1 . 13 Ila s2 x -gCj x dm - j x - 0 . lib Finally we demand non-negativity for the cross-sectional areas of the bars XL 0 for all i -- 1 -. - 13 - 12 c The constrained optimization problem is solved using an external penalty function by means of which the task is transformed into an unconstrained problem. With we state 26 f . 2 V x Ri2 max o gj x J i 1 2 3. 13 j l f gj x in the infeasible domain where max 0 gj X c in the feasible domain Here the choice of a suitable initial value for the penalty parameter Rj is crucial for the present task we choose R1 IQ-5 . The unconstrained problem 13 can be solved by means of suitable algorithms in the present case the POWELL -method of conjugate gradients has been used where a quadratic polynomium LAGRANGE-interpolation has proved sufficient for a one-dimensional minimization. In addition it could be shown that different initial designs Aj 100 . - 1000mm2 virtually lead to the same optimal solution. The calculation the scale of which requires the use of a computer yields the result that the force F is mostly carried via bars 4 to 8 into the supports 7 8 9 denoted by bold lines in Fig. D-3 . Consequently the remaining bars need very small cross-sectional areas only. Fig. D-3 Optimized truss structure by changing the cross-sections of the bars Exercise D-15 16-3 347 Exercise D15 16-3 Fig. D-4 shows a section of a circular cylindrical shell c with a ring stiffener s. The considered part of a boiler is subjected to a constant internal pressure p and has a constant inner temperature 0iC. The temperature distribution within boiler and stiffener has been determined by measurements for the cylindrical section c we assume a linear temperature distribution over the thickness with the gradient 10c const in the longitudinal direction ec z - 0C Z 0C with Op _ 0iC Ỡoc Ip 0OC 0iC yc - c

Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.