Combined Length Scale and Overhang Angle Control in Minimum Compliance Topology Optimization for Additive Manufacturing

2018 ◽  
pp. 361-371
Author(s):  
Jeroen Pellens ◽  
Geert Lombaert ◽  
Boyan Lazarov ◽  
Mattias Schevenels
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Length Scale ◽  
Minimum Compliance ◽  
Overhang Angle

Functional Performance Tailoring of Additively Manufactured Components via Topology Optimization

2017 ◽  
Author(s):  
John C. Steuben ◽  
John G. Michopoulos ◽  
Athanasios P. Iliopoulos ◽  
Andrew J. Birnbaum
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
High Performance ◽  
Functional Performance ◽  
Underwater Vehicle ◽  
Length Scale ◽  
Hand Tool ◽  
Component Shape ◽  
Future Work ◽  
Am Processes

The freedom of design that is afforded by Additive Manufacturing (AM) processes opens exciting possibilities for the production of lightweight, high performance components and structures. Consequently, in recent years the development of software tools to enable engineering design methods that exploit the unique features of AM has become a subject of increased research interest. In this paper we explore the use of Topology Optimization (TO) algorithms to tailor component shape in order to achieve the intended functionality of additively manufactured components at the macro length scale. We present two case studies: the first concerns the hierarchical nesting of functions in a hand tool, while the second covers the development of a metamaterial component substructure for an Uninhabited Underwater Vehicle (UUV) hull. We offer conclusions regarding the usefulness of TO techniques for the design of AM components, and a summary of future work, which we feel is necessary to improve such methodologies.

Additive manufacturing and topology optimization: A design strategy for a steering column mounting bracket considering overhang constraints

2020 ◽  
pp. 095440622091771
Author(s):  
Sara Mantovani ◽  
Giuseppe A Campo ◽  
Andrea Ferrari
Keyword(s):  
Finite Element ◽  
Topology Optimization ◽  
Additive Manufacturing ◽  
Isotropic Material ◽  
Element Model ◽  
The Body ◽  
Left Hand ◽  
Automotive Body ◽  
Body In White ◽  
Overhang Angle

In the present paper, the use of the topology optimization in a metal Additive Manufacturing application is discussed and applied to an automotive Body-in-White component called dash. The dash is in the front area of the Body-in-White, between the left-hand-side shock-tower and the Cross Car Beam, and its task is to support the steering column. The dash under investigation is an asymmetric rib-web aluminium casting part. The influence of Additive Manufacturing constraints together with modal and stiffness targets is investigated in view of mass reduction. The constraints drive the topology result towards a feasible and fully self-supporting Additive Manufacturing solution. A simplified finite element model of the steering column and of the Body-in-White front area is presented, and the limiting assumption of isotropic material for Additive Manufacturing is discussed. The optimization problem is solved with a gradient-based method relying on the Solid Isotropic Material with Penalization and on the RAtional Material with Penalization algorithms, considering the overhang angle constraint with given build directions. Three metals are tested: steel, aluminium and magnesium alloys. Topology optimization results with and without overhang angle constraints are discussed and compared. The aluminium solution, preferred for its lesser weight, has been preliminarily redesigned following the optimization results. The new dash concept has been validated by finite element considering stiffness, modal responses, and buckling resistance targets. The proposed dash design weighs 721 g compared to the 1537 g of the reference dash, with a weight reduction of 53%, for the same structural targets.

scholarly journals Integrated component-support topology optimization for additive manufacturing with post-machining

2019 ◽  
Vol 25 (2) ◽  
pp. 255-265 ◽  
Author(s):  
Matthijs Langelaar
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
High Performance ◽  
Process Model ◽  
Process Models ◽  
Content Type ◽  
Wide Range ◽  
Support Layout ◽  
Overhang Angle ◽  
Subtractive Machining

PurposeThe purpose of this paper is to communicate a method to perform simultaneous topology optimization of component and support structures considering typical metal additive manufacturing (AM) restrictions and post-print machining requirements.Design/methodology/approachAn integrated topology optimization is proposed using two density fields: one describing the design and another defining the support layout. Using a simplified AM process model, critical overhang angle restrictions are imposed on the design. Through additional load cases and constraints, sufficient stiffness against subtractive machining loads is enforced. In addition, a way to handle non-design regions in an AM setting is introduced.FindingsThe proposed approach is found to be effective in producing printable optimized geometries with adequate stiffness against machining loads. It is shown that post-machining requirements can affect optimal support structure layout.Research limitations/implicationsThis study uses a simplified AM process model based on geometrical characteristics. A challenge remains to integrate more detailed physical AM process models to have direct control of stress, distortion and overheating.Practical implicationsThe presented method can accelerate and enhance the design of high performance parts for AM. The consideration of post-print aspects is expected to reduce the need for design adjustments after optimization.Originality/valueThe developed method is the first to combine AM printability and machining loads in a single topology optimization process. The formulation is general and can be applied to a wide range of performance and manufacturability requirements.

Multicomponent Topology Optimization for Additive Manufacturing With Build Volume and Cavity Free Constraints

2019 ◽  
Vol 19 (2) ◽  
Author(s):  
Yuqing Zhou ◽  
Tsuyoshi Nomura ◽  
Kazuhiro Saitou
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Optimization Method ◽  
Simultaneous Optimization ◽  
Powder Bed ◽  
Optimization Framework ◽  
Minimum Compliance ◽  
Single Piece ◽  
Gradient Based ◽  
Length Width

Topology optimization for additive manufacturing has been limited to the design of single-piece components that fit within the printer's build volume. This paper presents a gradient-based multicomponent topology optimization method for structures assembled from components built by powder bed additive manufacturing (MTO-A), which enables the design of multipiece assemblies larger than the printer's build volume. Constraints on component geometry for powder bed additive manufacturing are incorporated in a density-based topology optimization framework, with an additional design field governing the component partitioning. For each component, constraints on the maximum allowable build volume (i.e., length, width, and height) and the elimination of enclosed cavities are imposed during the simultaneous optimization of the overall topology and component partitioning. Numerical results of the minimum compliance designs revealed that manufacturing constraints, previously applied to single-piece topology optimization, can unlock richer design exploration space when applied to multicomponent designs.

Local Redesign for Additive Manufacturability of Compliant Mechanisms Using Topology Optimization

2021 ◽  
Author(s):  
Stijn Koppen ◽  
Emma Hoes ◽  
Matthijs Langelaar ◽  
Mary I. Frecker
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Computational Effort ◽  
Manufacturing Constraints ◽  
Design For Additive Manufacturing ◽  
Computationally Efficient ◽  
Stress Levels ◽  
Overhang Angle

Abstract Compliant mechanisms are crucial components in current and future high-precision applications. Topology optimization and additive manufacturing offer freedom to design complex compliant mechanisms that were impossible to realize using conventional manufacturing. Design for additive manufacturing constraints, such as the maximum overhang angle and minimum feature size, tend to drastically decrease the performance of topology optimized compliant mechanisms. It is observed that, among others, design for additive manufacturing constraints are only dominant in the flexure regions. Flexures are most sensitive to manufacturing errors, experience the highest stress levels and removal of support material carries the highest risk of failure. It is crucial to impose these constraints on the flexure regions, while in others part of the compliant mechanism design, these constraints can be relaxed. We propose to first design the global compliant mechanism layout in the full domain without imposing any design for additive manufacturing constraints. Subsequently we redesign selected refined local redesign domains with design for additive manufacturing constraints, whilst simultaneously considering the mechanism performance. The method is applied to a single-input-multi-output compliant mechanism case study, limiting the maximum overhang angle, introducing manufacturing robustness and limiting the maximum stress levels of a selected refined redesign domain. The high resolution local redesigns are detailed and accurate, without a large additional computational effort or decrease in mechanism performance. Thereto, the method proves widely applicable, computationally efficient and effective in its purpose.

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