A PDE-Based Approach to Constrain the Minimum Overhang Angle in Topology Optimization for Additive Manufacturing

2017 ◽  
pp. 1185-1199 ◽  
Author(s):  
Emiel van de Ven ◽  
Can Ayas ◽  
Matthijs Langelaar ◽  
Robert Maas ◽  
Fred van Keulen
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Overhang Angle

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.

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.

scholarly journals A Shape Optimization Method for Part Design Derived from the Buildability Restrictions of the Directed Energy Deposition Additive Manufacturing Process

Designs ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 19
Author(s):  
Andreas K. Lianos ◽  
Harry Bikas ◽  
Panagiotis Stavropoulos
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Energy Deposition ◽  
Design Method ◽  
Current Trend ◽  
Internal Stresses ◽  
Material Distribution ◽  
Load Case ◽  
Design Elements ◽  
Industrial Sectors

The design methodologies and part shape algorithms for additive manufacturing (AM) are rapidly growing fields, proven to be of critical importance for the uptake of additive manufacturing of parts with enhanced performance in all major industrial sectors. The current trend for part design is a computationally driven approach where the parts are algorithmically morphed to meet the functional requirements with optimized performance in terms of material distribution. However, the manufacturability restrictions of AM processes are not considered at the primary design phases but at a later post-morphed stage of the part’s design. This paper proposes an AM design method to ensure: (1) optimized material distribution based on the load case and (2) the part’s manufacturability. The buildability restrictions from the direct energy deposition (DED) AM technology were used as input to the AM shaping algorithm to grant high AM manufacturability. The first step of this work was to define the term of AM manufacturability, its effect on AM production, and to propose a framework to estimate the quantified value of AM manufacturability for the given part design. Moreover, an AM design method is proposed, based on the developed internal stresses of the build volume for the load case. Stress tensors are used for the determination of the build orientation and as input for the part morphing. A top-down mesoscale geometric optimization is used to realize the AM part design. The DED Design for Additive Manufacturing (DfAM) rules are used to delimitate the morphing of the part, representing at the same time the freeform mindset of the AM technology. The morphed shape of the part is optimized in terms of topology and AM manufacturability. The topology optimization and AM manufacturability indicator (TMI) is introduced to screen the percentage of design elements that serve topology optimization and the ones that serve AM manufacturability. In the end, a case study for proof of concept is realized.

Sign in / Sign up

Export Citation Format

Share Document