Manufacturability-Oriented Ground Beam-Joint Topology Optimization for Multi-Piece Frame Structure Design

2007 ◽  
Author(s):  
Myung-Jin Kim ◽  
Gang-Won Jang ◽  
Yoon Young Kim
Keyword(s):  
Topology Optimization ◽  
Structural Modification ◽  
Joint Stiffness ◽  
Structure Design ◽  
Design Tool ◽  
Frame Structure ◽  
Structural Performance ◽  
Beam Model ◽  
Optimal Layout ◽  
Design Variables

Topology optimization is a useful design tool, but it often yields layouts difficult to manufacture without considerable post structural modification. As a result, its structural performance can be significantly deteriorated. To minimize the undesirable postprocessing, we aim to develop a manufacturability-oriented compliance-minimizing topology optimization using a ground beam model incorporating additional zero-length elastic joint elements. In the present formulation, design variables control the stiffness of zero-length elastic joints, not the stiffness of beams. Because joint stiffness values at the converged state can be utilized to select candidate assembly locations, the technique is extremely useful to design multi-piece frame structures. An optimal layout is also extracted based on the stiffness values. Because structural properties of ground beams can take only on discretely available values or remain unchanged for optimization process, no post structural modification is required in an actual manufacturing step.

Application of a Ground Beam-Joint Topology Optimization Method for Multi-Piece Frame Structure Design

2008 ◽  
Vol 130 (8) ◽  
Author(s):  
Myung-Jin Kim ◽  
Gang-Won Jang ◽  
Yoon Young Kim
Keyword(s):  
Topology Optimization ◽  
Optimization Technique ◽  
Joint Stiffness ◽  
Optimization Method ◽  
Structure Design ◽  
Frame Structure ◽  
Optimal Layout ◽  
Design Variables ◽  
Discrete Values ◽  
Topology Optimization Method

When a multipiece frame structure is designed, not only its topological layout but also assembly locations should be determined. This paper presents a compliance-minimizing topology optimization technique to determine an optimal layout configuration and to suggest candidate assembly locations. The technique employs a ground beam-joint model and places candidate assembly joints where the values of joint stiffness are relatively small. The zero-length joint elements have varying stiffness controlled by real-valued design variables. Because joint stiffness values at the converged state can be utilized to select candidate assembly locations along with their strengths, the technique is extremely useful in multipiece frame structure design. Because structural properties of ground beams can have only discrete values or remain unchanged for optimization process, no poststructural modification is required in an actual manufacturing step.

Additive Manufacturing-Oriented Design of Graded Lattice Structures Through Explicit Topology Optimization

2017 ◽  
Vol 84 (8) ◽  
Author(s):  
Chang Liu ◽  
Zongliang Du ◽  
Weisheng Zhang ◽  
Yichao Zhu ◽  
Xu Guo
Keyword(s):  
Topology Optimization ◽  
Structure Design ◽  
Lattice Structures ◽  
New Approach ◽  
Optimization Framework ◽  
Concurrent Optimization ◽  
Design Variables ◽  
Graded Material ◽  
Graded Lattice ◽  
Moving Morphable Components

In the present work, a new approach for designing graded lattice structures is developed under the moving morphable components/voids (MMC/MMV) topology optimization framework. The essential idea is to make a coordinate perturbation to the topology description functions (TDF) that are employed for the description of component/void geometries in the design domain. Then, the optimal graded structure design can be obtained by optimizing the coefficients in the perturbed basis functions. Our numerical examples show that the proposed approach enables a concurrent optimization of both the primitive cell and the graded material distribution in a straightforward and computationally effective way. Moreover, the proposed approach also shows its potential in finding the optimal configuration of complex graded lattice structures with a very small number of design variables employed under various loading conditions and coordinate systems.

Optimization on the Spot Welded Configuration of Vehicle Components Considering the Structural Performance

2006 ◽  
Vol 326-328 ◽  
pp. 957-962 ◽  
Author(s):  
J.S. Eom ◽  
B.H. Ju ◽  
N. Choi ◽  
J.M. Park ◽  
Byung Chai Lee ◽  
...  
Keyword(s):  
Welded Joints ◽  
Structure Design ◽  
Spot Weld ◽  
Structural Performance ◽  
Motor Industry ◽  
Structural Rigidity ◽  
Design Variables ◽  
Lower Control Arm ◽  
Vehicle Components ◽  
Spot Welded

In the motor industry, the number of spot welded points is closely related to overall cost of the vehicle assembly. A design based on experience is probable to lead redundant spot welded joints. Welded joints are critical in the structural performance, so it is hard to reduce the number. A measurable design index on the design of spot weld configuration is proposed in this study. We optimized the spot welding location and number in the lower control arm of the vehicle and automobile body, as far as the structure retained the structural stiffness. In order to ensure the requirements, we use a sizing optimization of each spot weld stiffness for the global structural rigidity. The survival index is defined the summation of resulted design variables, which is equal to the number of survival in the series of sizing optimizations. With this design index, one can optimally measure the importance of each spot weld joint and remove the redundant spot welds from the structure design.

scholarly journals Evaluasi Level Kinerja Bangunan Gedung Kayu Bertingkat Rendah Akibat Beban Gelombang

2021 ◽  
Vol 9 (1) ◽  
pp. 25-36
Author(s):  
Yosafat Aji Pranata ◽  
Fadlillah Ariani Suroso ◽  
Bernardinus Herbudiman
Keyword(s):  
Structure Design ◽  
Frame Structure ◽  
Structural Performance ◽  
Actual Condition ◽  
Sea Waves ◽  
Risk Area ◽  
Cross Sectional ◽  
High Risk Area ◽  
Internal Forces ◽  
Column Joint

Several coastal areas in Indonesia are at risk of moderate to high tsunami disasters, this is related to the condition that Indonesia is located in an earthquake high risk area. At this time there are many buildings located on the coast with a low-rise stilt house system with the main structural system, namely beams and columns using timber materials. The building structure design includes the performance evaluation process, namely strength, stiffness and structural stability. The purpose of this research is to study the evaluation behavior of performance levels, especially the strength and stiffness of low-rise timber buildings, namely the level of structural performance due to gravity and lateral loads, namely sea waves. The research scope is a three-story building with a beam and column frame structure system. Columns are circular and beams have a square cross section. The loads taken into account are gravity and lateral. The strengths discussed are the bending capacity of the beam and the compressive capacity of the column. In order to obtain building behavior that is closer to real conditions, especially in beam-column joints, secondary data is used, namely empirical data on the envelope load-deformation curve of the beam-column joint test results in the laboratory (modeled as link property). Evaluation of structural performance begins with structural analysis using SAP2000 software, to obtain internal forces and building drift. The results show that the use of link properties in beam-column joint joints in the timber building structures shows greater deformation results compared to rigid joint models, this indicates that modeling the structure with beam-column joint joints modeled as link property has an impact on building stiffness. Lower and represents the condition of a timber building with beam-column joint characteristics closer to the actual condition. The existence of a hole size in the column (to insert the beam) which is larger than the cross-sectional size of the beam results in the rotation of the joint not being zero and a slip occurs when the joint works to transmit internal forces.

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.

scholarly journals A Sequential Approach for Aerodynamic Shape Optimization with Topology Optimization of Airfoils

2021 ◽  
Vol 26 (2) ◽  
pp. 34
Author(s):  
Isaac Gibert Martínez ◽  
Frederico Afonso ◽  
Simão Rodrigues ◽  
Fernando Lau
Keyword(s):  
Topology Optimization ◽  
Shape Optimization ◽  
Volume Fraction ◽  
Optimization Techniques ◽  
Free Form ◽  
Aerodynamic Shape Optimization ◽  
Sequential Approach ◽  
Airfoil Surface ◽  
Aerodynamic Shape ◽  
Design Variables

The objective of this work is to study the coupling of two efficient optimization techniques, Aerodynamic Shape Optimization (ASO) and Topology Optimization (TO), in 2D airfoils. To achieve such goal two open-source codes, SU2 and Calculix, are employed for ASO and TO, respectively, using the Sequential Least SQuares Programming (SLSQP) and the Bi-directional Evolutionary Structural Optimization (BESO) algorithms; the latter is well-known for allowing the addition of material in the TO which constitutes, as far as our knowledge, a novelty for this kind of application. These codes are linked by means of a script capable of reading the geometry and pressure distribution obtained from the ASO and defining the boundary conditions to be applied in the TO. The Free-Form Deformation technique is chosen for the definition of the design variables to be used in the ASO, while the densities of the inner elements are defined as design variables of the TO. As a test case, a widely used benchmark transonic airfoil, the RAE2822, is chosen here with an internal geometric constraint to simulate the wing-box of a transonic wing. First, the two optimization procedures are tested separately to gain insight and then are run in a sequential way for two test cases with available experimental data: (i) Mach 0.729 at α=2.31°; and (ii) Mach 0.730 at α=2.79°. In the ASO problem, the lift is fixed and the drag is minimized; while in the TO problem, compliance minimization is set as the objective for a prescribed volume fraction. Improvements in both aerodynamic and structural performance are found, as expected: the ASO reduced the total pressure on the airfoil surface in order to minimize drag, which resulted in lower stress values experienced by the structure.

The Calculation of the Supporting Stress of Track Plate in Ballastless High-Speed Rail Structure

2011 ◽  
Vol 97-98 ◽  
pp. 3-9
Author(s):  
Yang Wang ◽  
Quan Mei Gong ◽  
Mei Fang Li
Keyword(s):  
Stress Distribution ◽  
High Speed ◽  
Design Theory ◽  
Moving Load ◽  
Structure Design ◽  
Track Structure ◽  
Beam Model ◽  
High Speed Rail ◽  
Slab Track ◽  
Ballastless Track

The slab track is a new sort of track structure, which has been widely used in high-speed rail and special line for passenger. However, the ballastless track structure design theory is still not perfect and can not meet the requirements of current high-speed rail and passenger line ballastless track. In this paper, composite beam method is used to calculate the deflection of the track plate and in this way the vertical supporting stress distribution of the track plate can be gotten which set a basis for the follow-up study of the dynamic stress distribution in the subgrade. Slab track plate’s bearing stress under moving load is analyzed through Matlab program. By calculation and analysis, it is found that the deflection of track plate and the rail in the double-point-supported finite beam model refers to the rate of spring coefficient of the fastener and the mortar.The supporting stress of the rail plate is inversely proportional to the supporting stress of the rail. The two boundary conditions of that model ,namely, setting the end of the model in the seams of the track plate or not , have little effect on the results. We can use the supporting stress of the track plates on state 1to get the distribution of the supporting stress in the track plate when bogies pass. Also, when the dynamic load magnification factor is 1.2, the track plate supporting stress of CRST I & CRST II-plate non-ballasted structure is around 40kPa.

Numerical Experiments in Using Voronoi Cell Finite Elements for Topology Optimization

2009 ◽  
Author(s):  
James M. Gibert ◽  
Georges M. Fadel
Keyword(s):  
Topology Optimization ◽  
Isotropic Material ◽  
Numerical Experiments ◽  
Voronoi Cell ◽  
Material Model ◽  
Topological Optimization ◽  
Advantages And Disadvantages ◽  
Compliance Minimization ◽  
Design Variables ◽  
Standard Linear

This paper provides two separate methodologies for implementing the Voronoi Cell Finite Element Method (VCFEM) in topological optimization. Both exploit two characteristics of VCFEM. The first approach utilizes the property that a hole or inclusion can be placed in the element: the design variables for the topology optimization are sizes of the hole. In the second approach, we note that VCFEM may mesh the design domain as n sided polygons. We restrict our attention to hexagonal meshes of the domain while applying Solid Isotropic Material Penalization (SIMP) material model. Researchers have shown that hexagonal meshes are not subject to the checker boarding problem commonly associated with standard linear quad and triangle elements. We present several examples to illustrate the efficacy of the methods in compliance minimization as well as discuss the advantages and disadvantages of each method.

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