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STARSTRUC: First Structural Optimization Software System In USA Market

STARSTRUC is a pioneering software system for structural optimization, developed by Dr. Adel Elsaie. It offers a comprehensive suite of tools for optimizing structures, with a rich history of development and application. STARSTRUC involves a meticulous design process and utilizes advanced algorithms to achieve minimum weight designs with various constraints. The software supports different elements such as beams, shells, and springs, providing an efficient platform for creating innovative structural designs.

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STARSTRUC: First Structural Optimization Software System In USA Market

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  1. STARSTRUC: FirstStructural Optimization Software System In USA Market http://www.usislam.org/star/star.htm Dr. Adel Elsaie, PHD, Aerospace Eng.  Dallas, TX, USA STARSTRUC Name STAR: Texas is called the Lone Star State, Structural Technology And Research Co: STAR. STRUC: From Structure.

  2. History of STARSTRUC University of Grenoble, France 1970, Postdoctoral fellowship to study structural optimization techniques. 1971: Optimization of Truss elements, Linear Programming. 1974-1975 University of Toronto, Assistant Prof:Mechanical Eng: PHD. Energy methods in structural optimization. Civil Eng: MSC. Optimization with steel sections. 1983: STARSTRUC: Minimum Weight. Elements: Beam, Shell, Spring. Constraints: Stress and deflection.

  3. Design Process

  4. Portal Frame Example

  5. STARSTRUC Input File 4 main section Control definition. TITL, NAME, OPTI/DCYC Geometry definition. Nodes/Elements Model definition. DVAR, MATE, LINK, SUPP Load definition. NLOA, PRES, BLOA, DCON, BCON, VCON Graphics definition. Geometry, deflections, mode shapes, summary of design cycles.

  6. STARSTRUC Input File TITLE VERN55 PORTAL FRAME ,STEEL COMMANDS, AISC $ ALLOW. , WITH DISP. COSTRAINTS Control NAME AME OPTIMIZE 0 DCYCLE 0,4 DPARAMETER 1 1 .05 2. NODE 1 $ Geometry 2 0 0 180 3 0 240 180 4 0 240 0 BEAM 1 1 2 3 $ W 12X40 2 2 3 1 $ W 18X35 3 3 4 1 $ W 12X40

  7. STARSTRUC Input File PROFILE 1 W 12X40 36 1 $ W 12X40 Model 2 W 18X35 36 1 $ W 18X35 DVLINK 1 1 1 3 2 2 1 2 2 1 MATERIAL 1 .283E-3 .3 29E3 0 21.6 $******UNITS KIPS IN******* MALINK1 1 1 3 SUPPORT 1 4 1 345 1 1 1 12 4 4 1 126

  8. STARSTRUC Input File LOAD 1 $ DL+LL Load BLOAD 2 2 1 2 2 .250 .250 0 240 DCONSTRAINT 2 3 1 2 .01 -.01 LOAD 2 $ CONCENTRATED LOAD NLOAD2 2 1 1 15. LOAD 3 $ COMBINE COMBINE 1 .75 2 .75 ENDF

  9. Structural Optimization of Cantilever Beam: A challengeSolve 5 equations & inequalitiesin 2 unknowns http://www.usislam.org/star/designExample.pdf

  10. Design Space

  11. STARSTRUC: Optimality Criteria Application of the optimality criteria approach involves two distinct steps: The first step consists of the derivation of a set of necessary conditions which must be satisfied at the optimum design. The next step is to construct an efficient iterative scheme (Recipe) that drives the initial trial design toward the optimum design.

  12. STARSTRUC Optimization Algorithm 1. Size constraints:D Lj < D j < D Uj j=1,...., nv (1)where D Lj and D Ujrepresent the lower and upper bounds of the design variable D j, and NV is the total number of design variables.

  13. Stress Constraints i,l < Ui i=1,....,ne l=1,....,nl (2) These constraints require that the tensile or compressive stressesi,l of the element i must not exceed the allowable upper bound for any of the loading case l. The total number of elements is ne and the total number of loadings is nl.

  14. Displacement constraints U L k,l < U k,l < U U k,l k=1,....,nd (3) The displacement of node k under load case l must not exceed specified upper and lower bounds, and nd is the total number of nodes with displacement constraints.

  15. Natural Frequencies Constraints f Ln < f n n=1,....,nf (4) where f Ln represents the lower bound of the structural frequency f n, and nf is the total number of frequency constraints

  16. Global Buckling Constraints P Lm < P m m=1,....,nm (5) where P Lm represents the lower bound of the critical buckling load factor P m, and nm is the total number of buckling load constraints. Local bucking is treated by design codes.

  17. Optimality Criteria The conditions (1) through (5) form a set of design constraints, each of which can be represented by a hypersurface in the design space. A design satisfying all the constraints is called a feasible design, and the portion of the design space containing all the feasible design points is called the feasible region.

  18. Optimality Criteria In general na constraints become active at a design point lying on the boundary of the feasible region gn(D)=0 n=1,...,na gn(D)<0 n=na+1....,nc (6) where gn represents any of the above constraints, na is the number of active constraints, and nc is the total number of constraints.

  19. Optimality Criteria The objective is to find a set of design variables which satisfies all the constraints and minimizes the structural weight ne W = ii D j (7) i = 1  where i is the unit weight of the element, and i is the design variable fraction. If the minimum cost rather than weight is the design objective, then i should be taken as the unit cost.

  20. Optimality Criteria Considering the classical Lagrange formulation for a constrained problem, a Lagrangian function can be written as:  na L(D,  ) = W(D) + n gn(D) (8) n=1 where n 's are the positive Lagrange multipliers. Differentiating the Lagrangian function with respect to the design variable D j, and setting the resulting equation to zero, gives:

  21. Optimality Criteria na  W = ii = - n gn (9) ------ n=1 ------  D j  D j i.e., na  1 n gn = -1 (10) n=1 -------- -------- ii  D j The left-hand side of equation (10) is called the optimization convergence factor, and is used to develop the recursive design formula.

  22. OPTIMIZATION OF THE EIGENPROBLEM The equation representing the motion of a structure subjected to membrane forces and vibrating with frequency is given by:  [K + KG] {Q} -  [M] {Q} = 0  Where [K] is the elastic stiffness matrix, [M] is the mass matrix, and [KG] is the geometric stiffness matrix. Three generalized eigenproblems can be identified from the above equation, and these are: Free vibration KG = 0 Buckling = 0 Prestressed vibration

  23. Buckling and Vibration ofSimply Supported Beam

  24. Optimization of 10 Bars Cantilever

  25. TEN BAR CANTILEVER - Stress Ratio

  26. SUMMARY OF THE DESIGN CYCLES – TEN BAR CANTILEVER - VERN10

  27. WINSTAR: Vern10 - 3 example DVAR 20 Starting weight: 8,393 lb DCYC 6 VERN10 OPT. weight: 4970 lb MAX SR 1.0 MAX DISP RATIO 1.028 DVAR 2 Starting weight: 1,756 lb DCYC 6 VERN10a OPT. weight: 5042 lb MAX SR 1.0 MAX DISP RATIO 1.010 DVAR 200 in. Starting weight: 74,770 lb DCYC 6 VERN10b OPT. weight: 5406 lb MAX SR 1.0 MAX DISP RATIO 1.020 DCYC=6 NASA/Sverdrup attests to the superiority of STARSTRUC Structural Optimization Algorithm when testing Vern10.dat example for the International Space Station.

  28. SUMMARY OF THE DESIGN CYCLES – TEN BAR CANTILEVER – VERN10a

  29. SUMMARY OF THE DESIGN CYCLES – TEN BAR CANTILEVER – VERN10b

  30. Aircraft Wing- Stress Ratio

  31. SUMMARY OF THE DESIGN CYCLES – TESTGD - DVAR =0.02

  32. SUMMARY OF THE DESIGN CYCLES – TESTGD5 - DVAR =0.50

  33. STARSTRUC Features Structural Optimization requires differentiating Structural matrices, NOT sizing members. Most of weight variation in the first 2 cycles. Always converge in about 4 cycles Results do not depend on starting design. Weight Reduction: 15%-50% Cost saving: Eng. Schedule, Weight of steel, transportation, Painting, Erection.

  34. Wrong Model: STARSTRUC screams at you 200 Ton Hydraulic Press 70 Meter Antenna

  35. 200 Ton Hydraulic Press

  36. 70-meter Antenna

  37. Future Development Of STARSTRUC - Dream List Adding sparse Matrix solution Update steel design codes of AISC and API. Concrete Design Codes, slabs, columns, reinforcement. Add optimization of composite Elements. Add practical design constraints on fracture Mechanics (crack growth), Fatigue, Creep, ..... Have better GUI (Graphics User Interface), i.e. enhance WINSTAR , better plotting capabilities, and reporting and fixing errors.

  38. Marketing Difficulties Engineers are conservative. Big software vendors control market. Professors have major advantage, COSMOS. Interface with ANSYS, NASTRAN, COSMOS. Legal: Weight reduction 15%-50%. ANSTAR, NASTAR, COSTAR. MICROSOFT: Compilers, OS, OFFICE. Learned from Time sharing market. Maximize Revenue. Marketing strategy: small number of big companies with good engineers who understand benefits.

  39. Successful Projects The National Missile defense in USA with Raytheon. Offshore structures with McDermott offshore. Wisdom, Shape Optimization, AI. Rockwell  (Marine division, torpedoes 4 lbs),  Space division (Missile parts) Landing gears of F-22 and F35 aircrafts with Menasco. Air intake structure of the F-16 with General Dynamics (now Lockheed Martin) Transmission steel towers for Nebraska Public Power District. Many steel/concrete structures/office buildings.

  40. National Missile Defense technet.idnes.cz/jak-bude-fungovat-americky-r...

  41. National Missile Defensehttp://www.blisty.cz/img/-4292.jpg?id=-4292&size=350&mg=0

  42. Muslim Association of Structural Optimization Professionals.  (MASOP). Small group of Professors to lead MASOP: Form the Association, direct and control Research and Development, Conferences. Transfer the ownership of STARSTRUC to MASOP. Commented Source Code. Increase awareness of Structural Optimization, undergraduate/graduate courses. Consulting group within MASOP to spread Technology.

  43. Jazakum Allah Khairan I hope, InShaa Allah, you become pioneers in Structural Optimization Dr. Adel Elsaie

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