mario.r
Guest
Hello.
as from title I am performing the design and optimization of a board for launch vehicles reinforced with only double t stringers. Such stringers are designed to have the same size for internal and external flange. the measurement system used is the Anglo-Saxon one. the design of the same happened by parameters (l= panel length, r= panel radius and tskin parameters, tweb,tfe,tfi for various thicknesses, bs for stringer spacing). the resolutive analysis focuses on the buckling and I have to design 3 different panels with lengths fixed to 300,400 and 500 inches. the panel is subject to a compression load of 1000 lb/in. the structural bond is the critical load factor (lambda) which must be greater than 1.2. the code for design and optimization has already been written but I meet various types of problems in the analysis of the first panel (which consequently I have also experienced in the panels from 400 and 500 inches):
1) small mesh leads to a number of high nodes for optimization (about 20000) and in optimization phase, after the first iteration, it stops because the program exceeds 32,000 nodes (limit for student license).
2) based on the values of the parameters, with fairly low values (l and r always remain the same and I cannot change them), ansys does not detect solutions neither static nor for the buckling and does not take the necessary volume for the minimization of the weight, also parameterized (weight=density*volume).
3)when I find an exact combination to obtain solution and volume, the program continues to optimize with solutions for lambda and weight of 99990000, values too high. eventually fails to achieve convergence.
My question is, where am I wrong?
below place the code I am using for the 300 in panel:
as from title I am performing the design and optimization of a board for launch vehicles reinforced with only double t stringers. Such stringers are designed to have the same size for internal and external flange. the measurement system used is the Anglo-Saxon one. the design of the same happened by parameters (l= panel length, r= panel radius and tskin parameters, tweb,tfe,tfi for various thicknesses, bs for stringer spacing). the resolutive analysis focuses on the buckling and I have to design 3 different panels with lengths fixed to 300,400 and 500 inches. the panel is subject to a compression load of 1000 lb/in. the structural bond is the critical load factor (lambda) which must be greater than 1.2. the code for design and optimization has already been written but I meet various types of problems in the analysis of the first panel (which consequently I have also experienced in the panels from 400 and 500 inches):
1) small mesh leads to a number of high nodes for optimization (about 20000) and in optimization phase, after the first iteration, it stops because the program exceeds 32,000 nodes (limit for student license).
2) based on the values of the parameters, with fairly low values (l and r always remain the same and I cannot change them), ansys does not detect solutions neither static nor for the buckling and does not take the necessary volume for the minimization of the weight, also parameterized (weight=density*volume).
3)when I find an exact combination to obtain solution and volume, the program continues to optimize with solutions for lambda and weight of 99990000, values too high. eventually fails to achieve convergence.
My question is, where am I wrong?
below place the code I am using for the 300 in panel:
for optimization instead:
Thank you in advance for any answers.