Parallel Optimization of Geometrically Nonlinear Truss Structures

2009 ◽  
Author(s):  
K.-R. Leimbach ◽  
D. Hartmann
Keyword(s):  
Truss Structures ◽  
Parallel Optimization ◽  
Geometrically Nonlinear

An Optimized Approach for Tracing Pre- and Post-Buckling Equilibrium Paths of Space Trusses

2019 ◽  
Vol 19 (04) ◽  
pp. 1950040
Author(s):  
Alireza Habibi ◽  
Shaahin Bidmeshki
Keyword(s):  
Nonlinear Behavior ◽  
Truss Structures ◽  
Equilibrium Path ◽  
Geometrically Nonlinear ◽  
Arc Length ◽  
Space Truss ◽  
Highly Nonlinear ◽  
Post Buckling ◽  
Space Trusses ◽  
Total Lagrangian Formulation

In this paper, a novel optimization-based method is proposed to analyze steel space truss structures undergoing large deformations. The geometric nonlinearity is considered using the total Lagrangian formulation. The nonlinear solution is obtained by introducing and minimizing an objective function subjected to the displacement-type constraints. The proposed approach can fully follow the equilibrium path of the geometrically nonlinear space truss structures not only before the limit point, but also after it, namely, including both the pre- and post-buckling paths. Moreover, a direct estimation of the buckling loads and their corresponding displacements is possible by using the method. Particularly, it has been shown that the equilibrium path of a structure with highly nonlinear behavior, multiple limit points, snap-through, and snap-back phenomena can be traced via the proposed algorithm. To demonstrate the accuracy, validity, and robustness of the proposed procedure, four benchmark truss examples are analyzed and the results compared with those by the modified arc-length method and those reported in the literature.

scholarly journals Analysis of damping ratio on the optimization of geometrically nonlinear truss structures subjected to dynamic loading

2020 ◽  
Vol 19 (3) ◽  
pp. 321-334
Author(s):  
Élcio Cassimiro Alves ◽  
◽  
Larissa Bastos Martinelli ◽  
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Loading ◽  
Geometric Nonlinearity ◽  
Numerical Models ◽  
Damping Ratio ◽  
Nonlinear Dynamic Analysis ◽  
Truss Structures ◽  
Geometrically Nonlinear ◽  
Cross Sectional ◽  
Updated Lagrangian

The objective of this paper is to present the formulation for optimizing truss structures with geometric nonlinearity under dynamic loads, provide pertinent case studies and investigate the influence of damping on the final result. The type of optimization studied herein aims to determine the cross-sectional areas that will minimize the weight of a given structural system, by imposing constraints on nodal displacements and axial stresses. The analyses are carried out using Sequential Quadratic Programming (SQP), available in MATLAB’s Optimization Toolbox™. The nonlinear finite space truss element is defined with an updated Lagrangian formulation, and the geometrically nonlinear dynamic analysis performed herein combines the Newmark method with Newton-Raphson iterations. The dynamic analysis approach was validated by comparing the results obtained with solutions available in the literature as well as with numerical models developed with ANSYS® 18.2. A number of optimization examples of planar and space trusses under dynamic loading with geometric nonlinearity are presented. Results indicate that the consideration of damping effects may lead to a significant reduction in structural weight and that such weight reduction is proportional to increases in damping ratio.

scholarly journals Optimization of geometrically nonlinear truss structures under dynamic loading

2020 ◽  
Vol 73 (3) ◽  
pp. 293-301
Author(s):  
Larissa Bastos Martinelli ◽  
Elcio Cassimiro Alves
Keyword(s):  
Dynamic Loading ◽  
Truss Structures ◽  
Geometrically Nonlinear

Dynamic analysis of geometrically nonlinear truss structures

1983 ◽  
Vol 17 (4) ◽  
pp. 491-497 ◽  
Author(s):  
S. Abrate ◽  
C.T. Sun
Keyword(s):  
Dynamic Analysis ◽  
Truss Structures ◽  
Geometrically Nonlinear
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