Topology Optimization for Stiffened Panels: A Ground Structure Method

2020 ◽  
Author(s):  
Jean-François Gamache ◽  
Aurelian Vadean ◽  
Nicolas Dodane ◽  
Sofiane Achiche
Keyword(s):  
Topology Optimization ◽  
Degrees Of Freedom ◽  
Setup Time ◽  
Optimization Method ◽  
Aviation Industry ◽  
Stiffened Panel ◽  
Truss Topology Optimization ◽  
Ground Structure ◽  
Stiffened Panels ◽  
Assembly Method

Abstract Reducing the weight of structures remains a major challenge in the aviation industry in order to reduce fuel consumption. The stiffened panel is the main assembly method for primary structures in aircraft, e.g. fuselage or wing. Density-based topology optimization has been used in research and in industry as a tool to help create new stiffening patterns for aircraft components, such as ribs, spars, bulkheads or even floor design. One critical aspect of stiffened panel design for wing structures is the buckling resistance. However, most work found in the literature does not include buckling analysis during optimization which leads to sub-optimal results when the stiffening layout is validated for buckling. Including buckling as a constraint for the density-based topology optimization has proven to be a complex task, mainly caused by the fact that the buckling of the stiffeners is not captured accurately. As such, this work presents an optimization method for stiffened panels based on the ground structure approach usually used for truss topology optimization. The main novelty of the method is the use of a stiffener activation variable (SAV) to activate only one variable at a time, either the height or density variable associated with each stiffeners of the ground structure. This work shows that while ground structure topology optimization requires more setup time and limiting the degrees of freedom of the optimization, it finds the best stiffening layout efficiently when compared to the density method.

An effective members-adding method for truss topology optimization based on principal stress trajectories

2017 ◽  
Vol 34 (6) ◽  
pp. 2088-2104 ◽  
Author(s):  
Ge Gao ◽  
Yaobin Li ◽  
Hui Pan ◽  
Limin Chen ◽  
Zhenyu Liu
Keyword(s):  
Topology Optimization ◽  
Principal Stress ◽  
Large Scale ◽  
Truss Topology Optimization ◽  
Force Transmission ◽  
Ground Structure ◽  
Element Analysis ◽  
Content Type ◽  
Truss Topology ◽  
Nodal Displacements

Purpose The purpose of this paper is to provide an effective members-adding method for truss topology optimization in plastic design. Design/methodology/approach With the help of the distribution of principal stress trajectories, obtained by finite element analysis of the design domain, ineffective zones for force transmission paths can be found, namely, areas whose nodes may have ersatz nodal displacements. Members connected by these nodes are eliminated and the reduced ground structure is used for optimization. Adding members in short to long order and limiting the number of members properly with the most strained ones added, large-scale truss problems in one load case and multiple-load cases are optimized. Findings Inefficient members (i.e. bars that fulfil the adding criterion but make no contribution to the optimal structure) added to the ground structure in each iterative step are reduced. Fewer members are used for optimization than before; therefore, faster solution convergence and less computation time are achieved with the optimized result unchanged. Originality/value The proposed members-adding method in the paper can alleviate the phenomenon of ersatz nodal displacements, enhance computational efficiency and save calculating resources effectively.

Performance Enhancement of Three-Dimensional Soil Structure Model via Optimization for Estimating Seismic Behavior of Buried Pipelines

2017 ◽  
Vol 11 (05) ◽  
pp. 1750019 ◽  
Author(s):  
Tsuyoshi Ichimura ◽  
Kohei Fujita ◽  
Atsushi Yoshiyuki ◽  
Pher Errol Quinay ◽  
Muneo Hori ◽  
...  
Keyword(s):  
Finite Element ◽  
Degrees Of Freedom ◽  
Performance Enhancement ◽  
Three Dimensional ◽  
Element Model ◽  
Optimization Method ◽  
Buried Pipelines ◽  
Ground Structure ◽  
3D Finite Element ◽  
Ground Structures

Damage to buried pipelines due to complex ground responses has been reported at residential development sites and valley plains with complex ground structures. Three-dimensional (3D) ground amplification analyses using 3D, nonlinear, finite-element methods may be effective in predicting such damage; however, it is often difficult to construct ground structures that are capable of reproducing observational characteristics. In this paper, we propose a 3D ground structure optimization method using a 3000[Formula: see text] forward finite-element dynamic analysis with approximately 0.27 million degrees of freedom, enabled by combining an automated 3D finite-element model-generation method and a fast 3D finite-element wave propagation analysis method. This optimization method is capable of estimating 3D ground structure models that can reproduce observational data characteristics. The effectiveness of the method is shown through an illustrative example.

Topology Optimization for Stiffened Panels: A Ground Structure Method

2021 ◽  
Author(s):  
Jean-Francois Gamache ◽  
Aurelian Vadean ◽  
Nicolas Dodane ◽  
Sofiane Achiche
Keyword(s):  
Topology Optimization ◽  
Ground Structure ◽  
Stiffened Panels ◽  
Ground Structure Method

scholarly journals Applications of truss topology optimization in the design of reinforced concrete structures using „Strut and Tie” models

2013 ◽  
Vol 12 (1) ◽  
pp. 091-098
Author(s):  
Karol Bołbotowski ◽  
Michał Knauff ◽  
Tomasz Sokół
Keyword(s):  
Topology Optimization ◽  
Reinforced Concrete ◽  
Truss Topology Optimization ◽  
Ground Structure ◽  
Structure Approach ◽  
Strut And Tie ◽  
Truss Topology ◽  
Practical Design ◽  
The Cost ◽  
Ground Structure Approach

Although Strut and Tie models are often used in practical design due to their apparent concept based on truss analysis, the creation of a model consistent with behaviour of the real structure is not an easy task. Frame corner model considered in the paper and presented in code [7] and article [8] exemplifies the problem. The authors proposed a method of automatic generating of ST models by making use of truss topology optimization (volume minimization problem). The method is based on classical ground structure approach. The authors introduced a method of including the cost of nodes in the objective function, which allowed to obtain solutions consisting of rationally small number of bars (unlike Michell’s structures). Moreover, algorithms ensuring consistency with Eurocode requirements were developed. The method was implemented in computer program. With the use of the software the authors proposed an alternative ST model for the frame corner, which requires considerably less reinforcement steel in comparison with the model suggested by the code. The versatility of the program was well proven in several other examples of plane stress problems in reinforced concrete design.

A new method to generate the ground structure in truss topology optimization

2016 ◽  
Vol 49 (2) ◽  
pp. 235-251 ◽  
Author(s):  
Ge Gao ◽  
Zhen-yu Liu ◽  
Yao-bin Li ◽  
Yan-feng Qiao
Keyword(s):  
Topology Optimization ◽  
New Method ◽  
Truss Topology Optimization ◽  
Ground Structure ◽  
Truss Topology

Origami Design by Topology Optimization

2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Kazuko Fuchi ◽  
Alejandro R. Diaz
Keyword(s):  
Topology Optimization ◽  
Design Method ◽  
Optimization Method ◽  
Optimal Combination ◽  
Ground Structure ◽  
Line Segments ◽  
Folding Pattern ◽  
Design Variables ◽  
3D Geometry ◽  
Dimensional Domain

An origami design method based on topology optimization is introduced. The design of a folding pattern is cast as a problem of assigning presence and type of fold to lines in a “ground structure,” using folding angles as design variables. A ground structure for origami design has lines drawn on a two dimensional domain, showing all line segments that may appear as crease lines in the folded geometry. For a given ground structure and folding angles, the 3D geometry of the folded sheet can be computed using the mathematics of origami. A topology optimization method is then used to find an optimal combination of folding angles, which results in a folding pattern with desired, target geometric properties.

scholarly journals Topology Optimization of Hard-Coating Thin Plate for Maximizing Modal Loss Factors

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 774
Author(s):  
Haitao Luo ◽  
Rong Chen ◽  
Siwei Guo ◽  
Jia Fu
Keyword(s):  
Topology Optimization ◽  
Objective Function ◽  
Composite Plates ◽  
Optimization Method ◽  
Hard Coating ◽  
Design Variables ◽  
Coating Composite ◽  
Damping Materials ◽  
Topology Optimization Method ◽  
Loss Factors

At present, hard coating structures are widely studied as a new passive damping method. Generally, the hard coating material is completely covered on the surface of the thin-walled structure, but the local coverage cannot only achieve better vibration reduction effect, but also save the material and processing costs. In this paper, a topology optimization method for hard coated composite plates is proposed to maximize the modal loss factors. The finite element dynamic model of hard coating composite plate is established. The topology optimization model is established with the energy ratio of hard coating layer to base layer as the objective function and the amount of damping material as the constraint condition. The sensitivity expression of the objective function to the design variables is derived, and the iteration of the design variables is realized by the Method of Moving Asymptote (MMA). Several numerical examples are provided to demonstrate that this method can obtain the optimal layout of damping materials for hard coating composite plates. The results show that the damping materials are mainly distributed in the area where the stored modal strain energy is large, which is consistent with the traditional design method. Finally, based on the numerical results, the experimental study of local hard coating composites plate is carried out. The results show that the topology optimization method can significantly reduce the frequency response amplitude while reducing the amount of damping materials, which shows the feasibility and effectiveness of the method.

Sign in / Sign up

Export Citation Format

Share Document