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Integrated topology and controller optimization using the Nyquist curve

Delissen, A.A.T.M. (author), van Keulen, A. (author), Langelaar, Matthijs (author)

The design of high-performance mechatronic systems is very challenging, as it requires delicate balancing of system dynamics, the controller, and their closed-loop interaction. Topology optimization provides an automated way to obtain systems with superior performance, although extension to simultaneous optimization of both topology and...

journal article 2023

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Classification and analysis of common simplifications in part-scale thermal modelling of metal additive manufacturing processes

Ranjan, R. (author), Langelaar, Matthijs (author), van Keulen, A. (author), Ayas, C. (author)

Computational process modelling of metal additive manufacturing has gained significant research attention in recent past. The cornerstone of many process models is the transient thermal response during the AM process. Since deposition-scale modelling of the thermal conditions in AM is computationally expensive, spatial and temporal...

journal article 2023

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Overheating control in additive manufacturing using a 3D topology optimization method and experimental validation

Ranjan, R. (author), Chen, Z. (author), Ayas, C. (author), Langelaar, Matthijs (author), van Keulen, A. (author)

Overheating is a major issue especially in metal Additive Manufacturing (AM) processes, leading to poor surface quality, lack of dimensional precision, inferior performance and/or build failures. A 3D density-based topology optimization (TO) method is presented which addresses the issue of local overheating during metal AM. This is achieved...

journal article 2023

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Towards improved porous models for solid/fluid topology optimization

Theulings, M.J.B. (author), Langelaar, Matthijs (author), van Keulen, A. (author), Maas, Robert (author)

Modeling of fluid flows in density-based topology optimization forms a longstanding challenge. Methods based on the Navier–Stokes equations with Darcy penalization (NSDP equations) are widely used in fluid topology optimization. These methods use porous materials with low permeability to represent the solid domain. Consequently, they suffer...

journal article 2023

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Controlling local overheating in topology optimization for additive manufacturing

Ranjan, R. (author), Ayas, C. (author), Langelaar, Matthijs (author), van Keulen, A. (author)

A novel constraint to prevent local overheating is presented for use in topology optimization (TO). The very basis for the constraint is the Additive Manufacturing (AM) process physics. AM enables fabrication of highly complex topologically optimized designs. However, local overheating is a major concern especially in metal AM processes...

journal article 2022

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Simultaneous topology and deposition direction optimization for Wire and Arc Additive Manufacturing

Mishra, V. (author), Ayas, C. (author), Langelaar, Matthijs (author), van Keulen, A. (author)

A remarkable elastic anisotropy in plates of austenitic stainless steel produced by the Wire and Arc Additive Manufacturing process is recently reported. The Young's modulus depends on the angle of orientation with respect to the material deposition direction. Here, for the first time, this anisotropy is exploited to maximize structural...

journal article 2022

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A simple and versatile topology optimization formulation for flexure synthesis

Koppen, S. (author), Langelaar, Matthijs (author), van Keulen, A. (author)

High-tech equipment critically relies on flexures for precise manipulation and measurement. Through elastic deformation, flexures offer extreme position repeatability within a limited range of motion in their degrees of freedom, while constraining motion in the degrees of constraint. Topology optimization proves a prospective tool for the...

journal article 2022

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Efficient multi-partition topology optimization

Koppen, S. (author), Langelaar, Matthijs (author), van Keulen, A. (author)

In topology optimization, the state of structures is typically obtained by numerically evaluating a discretized PDE-based model. The degrees of freedom of such a model can be partitioned in free and prescribed sets to define the boundary conditions. A multi-partition problem involves multiple partitions of the same discretization, typically...

journal article 2022

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Realization and assessment of metal additive manufacturing and topology optimization for high-precision motion systems

Delissen, A.A.T.M. (author), Boots, Elwin (author), Laro, Dick (author), Kleijnen, Harry (author), van Keulen, A. (author), Langelaar, Matthijs (author)

The design of high-precision motion stages, which must exhibit high dynamic performance, is a challenging task. Manual design is difficult, time-consuming, and leads to sub-optimal designs that fail to fully exploit the extended geometric freedom that additive manufacturing offers. By using topology optimization and incorporating all...

journal article 2022

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Design for drainability in density-based topology optimization

Giele, R.J.P. (author), van Keulen, A. (author), Langelaar, Matthijs (author)

Topology optimization methods improve the structural performance of components. However, in food processing, medical, high-precision, and other industries' designs should also fulfil the requirement of being cleanable. An important aspect of cleanability is drainability, which entails that fluids can always run off the structure under just...

journal article 2022

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A stress-based criterion to identify and control intersections in 2D compliance minimization topology optimization

Mishra, V. (author), Ayas, C. (author), Langelaar, Matthijs (author), van Keulen, A. (author)

Topology optimization typically generates designs that exhibit significant geometrical complexity, which can pose difficulties for manufacturing and assembly. The number of occurrences of an important design feature, in particular intersections, increases with geometrical complexity. Intersections are essential for load transfer in many...

journal article 2022

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Overhang control in topology optimization: a comparison of continuous front propagation-based and discrete layer-by-layer overhang control

van de Ven, E.A. (author), Maas, Robert (author), Ayas, C. (author), Langelaar, Matthijs (author), van Keulen, A. (author)

Although additive manufacturing (AM) allows for a large design freedom, there are some manufacturing limitations that have to be taken into consideration. One of the most restricting design rules is the minimum allowable overhang angle. To make topology optimization suitable for AM, several algorithms have been published to enforce a minimum...

journal article 2021

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Topology Optimization for additive manufacturing with distortion constraints

Misiun, Grzegorz (author), van de Ven, E.A. (author), Langelaar, Matthijs (author), Geijselaers, Hubert (author), van Keulen, A. (author), van den Boogaard, Ton (author), Ayas, C. (author)

An important cause of failure in powder bed additive manufacturing is the distortion of the part due to thermal shrinkage during printing and the relaxation of residual stresses after its release from the base plate. In this paper, Additive Manufacturing simulations are coupled with Topology Optimization in order to generate designs that are...

journal article 2021

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Accessibility of support structures in topology optimization for additive manufacturing

van de Ven, E.A. (author), Ayas, C. (author), Langelaar, Matthijs (author), Maas, Robert (author), van Keulen, A. (author)

Additive manufacturing (AM) and topology optimization (TO) have a synergetic relation, as AM can produce complex TO designs, and TO provides high-performance parts that utilize the form freedom provided by AM. Recently, TO has been tailored more toward AM with the inclusion of the minimum allowable overhang angle as a design constraint:...

journal article 2021

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Overhang control based on front propagation in 3D topology optimization for additive manufacturing

van de Ven, E.A. (author), Maas, Robert (author), Ayas, C. (author), Langelaar, Matthijs (author), van Keulen, A. (author)

It is attractive to combine topology optimization (TO) with additive manufacturing (AM), due to the design freedom provided by AM, and the increased performance that can be achieved with TO. One important aspect is to include the design rules associated with the process restrictions of AM to prevent the requirement of relatively large support...

journal article 2020

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Efficient limitation of resonant peaks by topology optimization including modal truncation augmentation

Delissen, A.A.T.M. (author), van Keulen, A. (author), Langelaar, Matthijs (author)

In many engineering applications, the dynamic frequency response of systems is of high importance. In this paper, we focus on limiting the extreme values in frequency response functions, which occur at the eigenfrequencies of the system, better known as resonant peaks. Within an optimization, merely sampling the frequency range and limiting the...

journal article 2020

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Fast Detection of Heat Accumulation in Powder Bed Fusion Using Computationally Efficient Thermal Models

Ranjan, R. (author), Ayas, C. (author), Langelaar, Matthijs (author), van Keulen, A. (author)

The powder bed fusion (PBF) process is a type of Additive Manufacturing (AM) technique which enables fabrication of highly complex geometries with unprecedented design freedom. However, PBF still suffers from manufacturing constraints which, if overlooked, can cause various types of defects in the final part. One such constraint is the local...

journal article 2020

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Design and analysis adaptivity in multi‐resolution topology optimization

Gupta, D.K. (author), van Keulen, A. (author), Langelaar, Matthijs (author)

Multiresolution topology optimization (MTO) methods involve decoupling of the design and analysis discretizations, such that a high‐resolution design can be obtained at relatively low analysis costs. Recent studies have shown that the MTO method can be approximately 3 and 30 times faster than the traditional topology optimization method for 2D...

journal article 2020

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Improving the manufacturability of metal AM parts

Sinico, Mirko (author), Ranjan, R. (author), Moshiri, Mandana (author), Ayas, C. (author), Langelaar, Matthijs (author), van Keulen, A. (author), Dewulf, Wim (author), Witvrouw, Ann (author)

Numerous challenges of additive manufacturing (AM) are tackled in the European Horizon 2020 project PAM^2 by studying and linking every step of the AM process cycle. For example, PAM^2 researchers from the design, processing and application side have collaborated in this work to optimise the manufacturability of metal AM parts using an improved...

journal article 2019

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On process-step parallel computability and linear superposition of mechanical responses in additive manufacturing process simulation

Munro, D.P. (author), Ayas, C. (author), Langelaar, Matthijs (author), van Keulen, A. (author)

We study linearity assumptions in the transient macroscale mechanical aspect of additive manufacturing (AM) process simulation. Linearity assumptions are often resorted to in combination with calibrated inelastic deformation components to arrive at computationally tractable yet reasonably accurate AM process models. We point out that...

journal article 2019