Anderson Pereira

Verified

Anderson verified their affiliation via an institutional email.

Learn more

Verified

Anderson verified their affiliation via an institutional email.

Learn more

• D.Sc.
• Professor (Adjoint) at Pontifical Catholic University of Rio de Janeiro

Topology optimization is a powerful engineering design tool that can lead to innovative layouts and significantly enhance the performance of engineered systems in various sectors. In a world where we are searching for cost reduction while being ecologically responsible, we should seek practical applications of topology optimization. Reducing weight...

This work addresses the challenging problem of structural optimization, specifically focusing on minimizing the mass of a structure while satisfying constraints related to natural frequencies. Traditional optimization methods that rely on gradient information are not suitable for such complex problems. To overcome this limitation, metaheuristic met...

This paper presents some virtual element method (VEM) applications for topology optimization of non-Newtonian fluid-flow problems in arbitrary two-dimensional domains. The objective is to design an optimal layout for the incompressible non-Newtonian fluid flow, governed by the Navier–Stokes–Brinkman equations, to minimize the viscous drag. The poro...

In topology optimization setting, we can cast a variety of problems into a weighted-sum of compliances minimization. Robust design, for example, is commonly addressed in the form of a finite sum of deterministic load cases scenarios. Another example is the optimization of structures subjected to dynamic loads using the equivalent static load method...

This paper deals with the applications of stochastic spectral methods for structural topology optimization in the presence of uncertainties. A non-intrusive polynomial chaos expansion is integrated into a topology optimization algorithm to calculate low-order statistical moments of the mechanical-mathematical model response. This procedure, known a...

Because of increased geometric freedom at a widening range of length scales and access to a growing material space, additive manufacturing has spurred renewed interest in topology optimization of parts with spatially varying material properties and structural hierarchy. Simultaneously, a surge of micro/nanoarchitected materials have been demonstrat...

Modeling void regions is one of the main challenges in topology optimization of geometrically nonlinear structures due to the excessive distortions of low-density elements. Several solutions to this problem have been suggested in the literature, including interpolation methods such as the Energy Interpolation scheme and the Additive Hyperelasticity...

The original version of this article unfortunately contains several errors introduced by the typesetter during the publishing process and which have been corrected.

We present a virtual element method (VEM)-based topology optimization framework using polyhedral elements, which allows for convenient handling of non-Cartesian design domains in three dimensions. We take full advantage of the VEM properties by creating a unified approach in which the VEM is employed in both the structural and the optimization phas...

Topology optimization of geometrically nonlinear structures based on the finite element method suffers from numerical instabilities. This is caused by excessive distortions in low-density regions within the design domain which can jeopardize or even result in non-convergence of the optimization process. In this article, an interpolation scheme is s...

Nonlinear phenomena are present in the majority of real-world structural problems. In structural optimization, several difficulties arise when nonlinear relations are considered in the problem formulation. Structural optimization with nonlinearities is challenging in different aspects, e.g. sensitivity analysis and numerous nonlinear analysis that...

Topology optimization in the time domain of structures subjected to time-dependent loads is usually computationally expensive, starting with the large number of time-dependent analyses that are required. Furthermore, the computational cost to evaluate the gradients of the response is significantly high and requires a large storage space. In this pa...

This paper deals with the applications of stochastic spectral methods for structural topology optimization in the presence of uncertainties. A non-intrusive polynomial chaos expansion is integrated into a topology optimization algorithm to calculate low-order statistical moments of the mechanical–mathematical model response. This procedure, known a...

We present a Matlab implementation of topology optimization for compliance minimization on unstructured polygonal finite element meshes that efficiently accommodates many materials and many volume constraints. Leveraging the modular structure of the educational code, PolyTop, we extend it to the multi-material version, PolyMat, with only a few modi...

This work aims to evaluate the efficiency and robustness of the cross-entropy (CE) method in the context of structural optimization. A two-dimensional truss subject to vertical loads is used as a benchmark test, where one seeks to minimize the structure weight, respecting a structural integrity criterion. The optimal results obtained via CE are com...

This work aims to evaluate the efficiency and robustness of the cross-entropy (CE) method in the context of structural optimization. A two-dimensional truss subject to vertical loads is used as a benchmark test, where one seeks to minimize the structure weight, respecting a structural integrity criterion. The optimal results obtained via CE are com...

Talk at CNMAC 2018

The objective of topology optimization is to find the most efficient distribution of material (optimal topology) in a given domain, subjected to design constraints defined by the user. The quality of the new boundary representation depends on the level of mesh refinement: The greater the number of elements in the mesh, the better is the representat...

Most topology optimization applications in elasticity problems are limited to linear elastic materials and small deformations. However, there are many problems which depict large displacements and a nonlinear theory is required. For loads which magnitudes are within the nonlinear regime, the final shape changes significantly when the optimization c...

The design of a structure does not only imply compliance with the requirements of safety, strength, functionality, and total cost of construction, but also its ability to respond to optimizations standards pre-defined. Traditionally, the development of a structural design is based on scientific knowledge, empirical knowledge, and engineering team e...

A methodology for solving three-dimensional topology optimization problems through a two-level mesh representation approach is described and evaluated. Structural topology optimization problems are executed on a polytope-based mesh, which carries the design variable (and subsequently the density). Displacement field is determined using tetrahedron...

This work addresses topology optimization with stress constraints using the damage approach by Verbart et al. (2016) through a polygonal element discretization in the spirit of the PolyTop code (Talischi et al., 2012b). In order to limit the maximum stress on the final structure, material in overstressed regions is considered damaged and so contrib...

We present a Matlab implementation of topology optimization for fluid flow problems in the educational computer code PolyTop (Talischi et al. 2012b). The underlying formulation is the well-established porosity approach of Borrvall and Petersson (2003), wherein a dissipative term is introduced to impede the flow in the solid (non-fluid) regions. Pol...

A spectral stochastic approach for structural topology optimization in the presence of uncertainties in the magnitude and direction of the applied loads is proposed. The application of this approach in the representation and propagation of uncertainties presents a low computational cost compared to classical techniques, such as Monte Carlo simulati...

This paper presents the PolyTop++, an efficient and modular framework for parallel structural topology optimization using polygonal meshes. It consists of a C++ and CUDA (a parallel computing model for GPUs) alternative implementations of the PolyTop code by Talischi et al. (Struct Multidiscip Optim 45(3):329–357 2012b). PolyTop++ was designed to s...

Previous studies have shown that the commonly used quadrature schemes for polygonal and polyhedral finite elements lead to consistency errors that persist under mesh refinement and subsequently render the approximations non-convergent. In this work, we consider minimal perturbations to the gradient field at the element level in order to restore pol...

We present a method to generate polyhedral meshes in arbitrary domains that are suitable for use in numerical analysis involving methods such as finite elements or virtual elements. Previous work on polyhedral mesh generation consisted of computing Voronoi tessellations and using Lloyd's algorithm to obtain mesh regularity, i.e., removing excessive...

This paper describes an ongoing work in the development of a finite element analysis system, called TopFEM, based on the compact topological data structure, TopS and . This new framework was written to take advantage of the topological data structure together with object-oriented programming concepts to handle a variety of finite element problems,...

We discuss the use of polygonal finite elements for analysis of incompressible flow problems. It is well‐known that the stability of mixed finite element discretizations is governed by the so‐called inf‐sup condition, which, in this case, depends on the choice of the discrete velocity and pressure spaces. We present a low‐order choice of these spac...

Polygonal elements have been successfully applied to structural topology optimization by preventing the appearance of numerical instabilities such as checkerboard pattern and one-node connections. These anomalies are typically presented in grids of linear triangles and bilinear quads. In the analysis of incompressible flow problems, similar numeric...

We present a simple and robust Matlab code for polygonal mesh generation that relies on an implicit description of the domain geometry. The mesh generator can provide, among other things, the input needed for finite element and optimization codes that use linear convex polygons. In topology optimization, polygonal discretizations have been shown no...

We present an efficient Matlab code for structural topology optimization that includes a general finite element routine based on isoparametric polygonal elements which can be viewed as the extension of linear triangles and bilinear quads. The code also features a modular structure in which the analysis routine and the optimization algorithm are sep...

This paper presents an effective MATLAB implementation of a general topology optimization method for compliant mechanism synthesis of statically loaded structures. Our implementation is based on the educational framework PolyTop (Talischi et al., 2011b), which is easily extended to handle compliant mechanism design. The main features of PolyTop are...

Nonlinear problems are prevalent in structural and continuum mechanics, and there is high demand for computational tools to solve these problems. Despite efforts to develop efficient and effective algorithms, one single algorithm may not be capable of solving any and all nonlinear problems. A brief review of recent nonlinear solution techniques is...

In topology optimization literature, the parameterization of design is commonly carried out on uniform grids consisting of Lagrangian-type finite elements (e.g. linear quads). These formulations, however, suffer from numerical anomalies such as checkerboard patterns and one-node connections, which has prompted extensive research on these topics. A...

Superelements offer several advantages for high-fidelity solutions of topology optimization problems. Thus this work proposes the use of a two-level mesh representation, involving finite element and topology optimization variables. The proposed mapping–based framework provides a general approach to solve either two-dimensional or three-dimensional...

Traditionally, standard Lagrangian-type finite elements, such as linear quads and triangles, have been the elements of choice in the field of topology optimization. In general, finite element meshes with these elements exhibit the well-known checkerboard pathology in the iterative solution of topology optimization problems. Voronoi and Wachspress-t...