Topology optimization for infill in MEx

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Matt Schmitt ◽  
Il Yong Kim
Keyword(s):  
Topology Optimization ◽  
Numerical Optimization ◽  
Optimization Technique ◽  
Problem Formulation ◽  
Optimization Techniques ◽  
Manufacturing Constraints ◽  
Support Material ◽  
Element Mesh ◽  
Content Type ◽  
Manufacturing Method

Purpose In furthering numerical optimization techniques for the light-weighting of components, it is paramount to produce algorithms that closely mimic the physical behavior of the specific manufacturing method under which they are created. The continual development in topology optimization (TO) has reduced the difference in the optimized geometry from what can be physically realized. As the reinterpretation stage inevitably deviates from the optimal geometry, each progression in the optimization code that renders the final solution more realistic is beneficial. Despite the efficacy of material extrusion (MEx) in producing complex geometries, select manufacturing constraints are still required. Thus, the purpose of this paper is to develop a TO code which demonstrates the incorporation of MEx specific manufacturing constraints into a numerical optimization algorithm. Design/methodology/approach A support index is derived for each element of the finite element mesh that is used to penalize elements, which are insufficiently supported, discouraging their existence. The support index captures the self-supporting angle and maximum allowable bridging distance for a given MEx component. The incorporation of the support index into a TO code is used to demonstrate the efficacy of the method on multiple academic examples. Findings The case studies presented demonstrate the methodology is successful in generating a resulting topology that is self-supporting given the manufacturing parameters specified in the code. Comparative to a general TO problem formulation, the optimal material distribution results in a minimally penalized design on a compliance normalization metric while fully adhering to the MEx specific parameters. The methodology, thus, proves useful in generating an infill geometry is fully enclosed regions, where support material extraction is not a possibility. Originality/value The work presented is the first paper to produce a novel methodology that incorporates the manufacturing-specific constraint of bridging distance for MEx into TO code. The results generated allow for the creation of printed components with hollow inclusions that do not require any additional support material beyond the intended structure. Given the advancement, the numerical optimization technique has progressed to a more realistic representation of the physical manufacturing method.

Adapting Ant Colony for Topology Optimization of Compliant Mechanisms With Variable Material Density

2017 ◽  
Author(s):  
Nadim Diab
Keyword(s):  
Topology Optimization ◽  
Ant Colony Optimization ◽  
High Performance ◽  
Compliant Mechanisms ◽  
Optimization Technique ◽  
Optimization Techniques ◽  
Ant Colony ◽  
Intensity Level ◽  
Material Density ◽  
Swarm Intelligence Optimization

Swarm intelligence optimization techniques are widely used in topology optimization of compliant mechanisms. The Ant Colony Optimization has been implemented in various forms to account for material density distribution inside a design domain. In this paper, the Ant Colony Optimization technique is applied in a unique manner to make it feasible to optimize for the beam elements’ cross-section and material density simultaneously. The optimum material distribution algorithm is governed by two various techniques. The first technique treats the material density as an independent design variable while the second technique correlates the material density with the pheromone intensity level. Both algorithms are tested for a micro displacement amplifier and the resulting optimized topologies are benchmarked against reported literature. The proposed techniques culminated in high performance and effective designs that surpass those presented in previous work.

Efficient Structural Design Using a Numerical Optimization Technique

2019 ◽  
Author(s):  
Qian Wang ◽  
Lucas Schmotzer ◽  
Yongwook Kim
Keyword(s):  
Structural Design ◽  
Numerical Optimization ◽  
Optimization Technique ◽  
Optimization Method ◽  
Optimization Techniques ◽  
Convergence Criteria ◽  
Efficient Design ◽  
Concrete Building ◽  
Gradient Based ◽  
Structural Responses

<p>Structural designs of complex buildings and infrastructures have long been based on engineering experience and a trial-and-error approach. The structural performance is checked each time when a design is determined. An alternative strategy based on numerical optimization techniques can provide engineers an effective and efficient design approach. To achieve an optimal design, a finite element (FE) program is employed to calculate structural responses including forces and deformations. A gradient-based or gradient-free optimization method can be integrated with the FE program to guide the design iterations, until certain convergence criteria are met. Due to the iterative nature of the numerical optimization, a user programming is required to repeatedly access and modify input data and to collect output data of the FE program. In this study, an approximation method was developed so that the structural responses could be expressed as approximate functions, and that the accuracy of the functions could be adaptively improved. In the method, the FE program was not required to be directly looped in the optimization iterations. As a practical illustrative example, a 3D reinforced concrete building structure was optimized. The proposed method worked very well and optimal designs were found to reduce the torsional responses of the building.</p>

Evolutionary Topology Optimization of Spatial Steel-Concrete Structures

2021 ◽  
Vol 62 (2) ◽  
pp. 102-112
Author(s):  
Yu Li ◽  
Yi Min Xie
Keyword(s):  
Topology Optimization ◽  
Composite Structures ◽  
Optimization Technique ◽  
Optimization Techniques ◽  
Principal Stresses ◽  
Element Analysis ◽  
Floor Systems ◽  
Beso Method ◽  
Multiple Materials ◽  
Single Material

Topology optimization techniques based on finite element analysis have been widely used in many fields, but most of the research and applications are based on single-material structures. Extended from the bi-directional evolutionary structural optimization (BESO) method, a new topology optimization technique for 3D structures made of multiple materials is presented in this paper. According to the sum of each element's principal stresses in the design domain, a material more suitable for this element would be assigned. Numerical examples of a steel- concrete cantilever, two different bridges and four floor systems are provided to demonstrate the effectiveness and practical value of the proposed method for the conceptual design of composite structures made of steel and concrete.

Generative Adversarial Networks With Synthetic Training Data for Enforcing Manufacturing Constraints on Topology Optimization

2020 ◽  
Author(s):  
Michael Greminger
Keyword(s):  
Topology Optimization ◽  
Vector Space ◽  
Training Data ◽  
Generative Adversarial Networks ◽  
Manufacturing Constraints ◽  
Cnc Milling ◽  
Manufacturing Method ◽  
Latent Vector ◽  
Adversarial Networks ◽  
Manufacturing Methods

Abstract Topology optimization is a powerful tool to generate mechanical designs that use minimal mass to achieve their function. However, the designs obtained using topology optimization are often not manufacturable using a given manufacturing process. There exist some modifications to the traditional topology optimization algorithm that are able to impose manufacturing constraints for a limited set of manufacturing methods. These approaches have the drawback that they are often based on heuristics to obtain the manufacturability constraint and thus cannot be applied generally to multiple manufacturing methods. In order to create a general approach to imposing manufacturing constraints on topology optimization, generative adversarial networks (GANs) are used. GANs have the capability to produce samples from a distribution defined by training data. In this work, the GAN is trained by generating synthetic 3D voxel training data that represent the distribution of designs that can be created by a particular manufacturing method. Once trained, the GAN forms a mapping from a latent vector space to the space of manufacturable designs. The topology optimization is then performed on the latent vector space ensuring that the design obtained is manufacturable. The effectiveness of this approach is demonstrated by training a GAN on designs intended to be manufacturable on a 3-axis computer numerically controlled (CNC) milling machine.

Design and Development of XY Micro-Positioning Stage Using Modified Topology Optimization Technique

2014 ◽  
Vol 592-594 ◽  
pp. 2220-2224 ◽  
Author(s):  
T. Ramesh ◽  
Ramalingam Bharanidaran ◽  
V. Gopal
Keyword(s):  
Finite Element Method ◽  
Topology Optimization ◽  
Compliant Mechanism ◽  
Optimization Technique ◽  
Optimization Techniques ◽  
Structural Performance ◽  
Interpolation Function ◽  
Positioning Stage ◽  
Final Design ◽  
Node Connectivity

XY positioning stages are fundamental components during precision manipulation of micro sized objects. A compliant mechanism based mechanism is the appropriate choice for the design of XY stage. Topology optimization techniques are utilized to design the compliant mechanism. During the process of topology optimization, senseless regions are appearing from the manufacturability perspective. Senseless regions are staircase boundaries and node to node connectivity which is impossible to manufacture. Interpolation function is included in the topology optimization to minimize the effect of senseless regions. However topologically developed design is post processed to attain the manufacturability. Structural performance of the post processed final design is validated through Finite Element Method (FEM) and experimental technique.

scholarly journals Topology optimization of a novel fuselage structure in the conceptual design phase

2018 ◽  
Vol 90 (9) ◽  
pp. 1385-1393
Author(s):  
Dianzi Liu ◽  
Chuanwei Zhang ◽  
Z. Wan ◽  
Z. Du
Keyword(s):  
Topology Optimization ◽  
Optimization Technique ◽  
Design Tool ◽  
Computational Time ◽  
Element Analysis ◽  
Content Type ◽  
Shell Elements ◽  
Upper And Lower Extremities ◽  
German Aerospace ◽  
Comparison Of The Results

Purpose In recent years, innovative aircraft designs have been investigated by researchers to address the environmental and economic issues for the purpose of green aviation. To keep air transport competitive and safe, it is necessary to maximize design efficiencies of the aircrafts in terms of weight and cost. The purpose of this paper is to focus on the research which has led to the development of a novel lattice fuselage design of a forward-swept wing aircraft in the conceptual phase by topology optimization technique. Design/methodology/approach In this paper, the fuselage structure is modelled with two different types of elements – 1D beam and 2D shell – for the validation purpose. Then, the finite element analysis coupled with topology optimization is performed to determine the structural layouts indicating the efficient distributed reinforcements. Following that, the optimal fuselage designs are obtained by comparison of the results of 1D and 2D models. Findings The topological results reveal the need for horizontal stiffeners to be concentrated near the upper and lower extremities of the fuselage cross section and a lattice pattern of criss-cross stiffeners should be well-placed along the sides of the fuselage and near the regions of window locations. The slight influence of windows on the optimal reinforcement layout is observed. To form clear criss-cross stiffeners, modelling the fuselage with 1D beam elements is suggested, whereas the less computational time is required for the optimization of the fuselage modelled using 2D shell elements. Originality/value The authors propose a novel lattice fuselage design in use of topology optimization technique as a powerful design tool. Two types of structural elements are examined to obtain the clear reinforcement detailing, which is also in agreement with the design of the DLR (German Aerospace Center) demonstrator. The optimal lattice layout of the stiffeners is distinctive to the conventional semi-monocoque fuselage design and this definitely provides valuable insights into the more efficient utilization of composite materials for novel aircraft designs.

Multistage topology optimization of induction heating apparatus in time domain electromagnetic field with magnetic nonlinearity

2019 ◽  
Vol 38 (3) ◽  
pp. 1009-1022
Author(s):  
Hiroshi Masuda ◽  
Yoshifumi Okamoto ◽  
Shinji Wakao
Keyword(s):  
Finite Element ◽  
Topology Optimization ◽  
Induction Heating ◽  
Time Domain ◽  
Computation Time ◽  
Design Domain ◽  
Element Mesh ◽  
Content Type ◽  
Actual Application ◽  
Application Model

Purpose The purpose of this paper is to solve efficiently the topology optimization (TO) in time domain problem with magnetic nonlinearity requiring a large-scale finite element mesh. As an actual application model, the proposed method is applied to induction heating apparatus. Design/methodology/approach To achieve TO with efficient computation time, a multistage topology is proposed. This method can derive the optimum structure by repeatedly reducing the design domain and regenerating the finite element mesh. Findings It was clarified that the structure derived from proposed method can be similar to the structure derived from the conventional method, and that the computation time can be made more efficient by parameter tuning of the frequency and volume constraint value. In addition, as a time domain induction heating apparatus problem of an actual application model, an optimum topology considering magnetic nonlinearity was derived from the proposed method. Originality/value Whereas the entire design domain must be filled with small triangles in the conventional TO method, the proposed method requires finer mesh division of only the stepwise-reduced design domain. Therefore, the mesh scale is reduced, and there is a possibility that the computation time for TO can be shortened.

scholarly journals On understanding of design problem formulation for compliant mechanisms through topology optimization

2013 ◽  
Vol 4 (2) ◽  
pp. 357-369 ◽  
Author(s):  
L. Cao ◽  
A. Dolovich ◽  
W. J. Zhang
Keyword(s):  
Topology Optimization ◽  
Compliant Mechanisms ◽  
Optimization Technique ◽  
Problem Formulation ◽  
Functional Requirements ◽  
Motion Generation ◽  
Design Problems ◽  
Standard Design ◽  
Quantitative Design ◽  
Future Work

Abstract. General problems associated with the design of compliant mechanisms through the topology optimization technique are defined in this paper due to the lack of comprehensive definitions for these problems in the literature. Standard design problems associated with rigid body mechanisms, i.e. function generation, path generation and motion generation, are extended to compliant mechanisms. Functional requirements and the associated 25 formulations in the literature are comprehensively reviewed along with their limitations. Based on whether the output is controlled quantitatively or not, these formulations are categorized into two types: (1) formulations for quantitative design; and (2) formulations for qualitative design. In addition, formulations that aim to solve the point flexure problem are also discussed. Future work is identified based on the discussion of each topic.

Design of a Micromixer With Herringbone Grooves Using Numerical Optimization Techniques

2007 ◽  
Author(s):  
Mubashshir Ahmad Ansari ◽  
Kwang-Yong Kim
Keyword(s):  
Spatial Data ◽  
Numerical Optimization ◽  
Optimization Technique ◽  
Three Dimensional ◽  
Groove Depth ◽  
Optimization Techniques ◽  
Navier Stokes ◽  
Channel Height ◽  
Design Variables ◽  
Data Statistics

Optimization of a staggered herringbone groove micromixer has been performed by using three-dimensional Navier-Stokes analysis. The analysis of the degree of mixing is performed by the calculation of spatial data statistics. The calculation of the variance of the mass fraction at various nodes on a plane in the channel is used to quantify mixing. A numerical optimization technique is applied to optimize the shape of the grooves on a single wall of the channel. Two design variables, namely, the ratio of the groove depth to channel height and the angle of the groove, are selected for optimization. A mixing index is used as the objective function. The results of the optimization show that the mixing is very sensitive to the shape of the groove which can be used in controlling mixing in microdevices.

Optimal Linkage Shapes of Planar Mechanisms Using Topology Optimization

2016 ◽  
Author(s):  
Nathan Berge ◽  
Matthew I. Campbell
Keyword(s):  
Topology Optimization ◽  
Static Loading ◽  
Numerical Optimization ◽  
Optimization Algorithms ◽  
Optimization Technique ◽  
Inertial Forces ◽  
Planar Mechanisms ◽  
And Topology ◽  
Two Systems ◽  
Walking Mechanism

Through the methods outlined in this paper, a procedure involving two cooperating optimization algorithms is developed to create balanced, structurally optimal planar mechanisms. Two systems are analyzed to demonstrate the approach. In the first example, a walking mechanism is analyzed under quasi-static loading, and topology optimization is performed to create stiff, lightweight linkages. In the second example, a quick-return Watt-II six-bar mechanism, counterweights are added to balance the mechanism using a numerical optimization technique. The inertial forces are calculated by simulation, and optimal linkage shapes are generated to support them using topology optimization.

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