Building Block-Based Spatial Topology Synthesis Method for Large-Stroke Flexure Hinges

2017 ◽  
Vol 9 (4) ◽  
Author(s):  
M. Naves ◽  
D. M. Brouwer ◽  
R. G. K. M. Aarts
Keyword(s):  
Shape Optimization ◽  
Building Block ◽  
Synthesis Method ◽  
Solution Space ◽  
Building Blocks ◽  
Optimization Method ◽  
Mode Shapes ◽  
Flexure Hinges ◽  
Spatial Topology ◽  
Block Based

Large-stroke flexure mechanisms inherently lose stiffness in supporting directions when deflected. A systematic approach to synthesize such hinges is currently lacking. In this paper, a new building block-based spatial topology synthesis method is presented for optimizing large-stroke flexure hinges. This method consists of a layout variation strategy based on a building block approach combined with a shape optimization to obtain the optimal design tuned for a specific application. A derivative-free shape optimization method is adapted to include multiple system boundaries and constraints to optimize high complexity flexure mechanisms in a broad solution space. To obtain the optimal layout, three predefined three-dimensional (3D) “building blocks” are proposed, which are consecutively combined to find the best layout with respect to specific design criteria. More specifically, this new method is used to optimize a flexure hinge aimed at maximizing the frequency of the first unwanted vibration mode. The optimized topology shows an increase in frequency of a factor ten with respect to the customary three flexure cross hinge (TFCH), which represents a huge improvement in performance. The numerically predicted natural frequencies and mode shapes have been verified experimentally.

scholarly journals Multibody-Based Topology Synthesis Method for Large Stroke Flexure Hinges

2016 ◽  
Author(s):  
M. Naves ◽  
D. M. Brouwer ◽  
R. G. K. M. Aarts
Keyword(s):  
Shape Optimization ◽  
Synthesis Method ◽  
Solution Space ◽  
Building Blocks ◽  
Optimization Method ◽  
Mode Shapes ◽  
Optimal Layout ◽  
Flexure Hinges ◽  
Derivative Free ◽  
Block Approach

Large stroke flexure mechanisms inherently lose stiffness in supporting directions when deflected due to load components in compliant bending and torsion directions. To maximize performance over the entire range of motion, a topology optimization suited for large stroke mechanisms is required. In this paper a new multibody-based topology synthesis method is presented for optimizing large stroke flexure hinges. This topology synthesis consists of a layout variation strategy based on a building block approach combined with a shape optimization to obtain the optimal design tuned for a specific application. A derivative free shape optimization method is used to optimize high complexity flexure mechanisms in a broad solution space. To obtain the optimal layout, three predefined “building blocks” are proposed which are consecutively combined to find the best layout with respect to a specific design criteria. More specifically, this new method is used to optimize a flexure hinge aimed at maximizing the first disturbing eigenfrequency. The optimized topology shows an increase in frequency of a factor ten with respect to the customary three flexure cross hinge, which represents a huge improvement in performance. The numerically predicted natural frequencies and mode shapes have been verified experimentally.

Conceptual designs of multi-degree of freedom compliant parallel manipulators composed of wire-beam based compliant mechanisms

2014 ◽  
Vol 229 (3) ◽  
pp. 538-555 ◽  
Author(s):  
Guangbo Hao ◽  
Haiyang Li
Keyword(s):  
Rigid Body ◽  
Building Block ◽  
Compliant Mechanisms ◽  
Building Blocks ◽  
Parallel Manipulators ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Conceptual Designs ◽  
Rigid Body Model ◽  
Block Based

This paper proposes conceptual designs of multi-degree(s) of freedom (DOF) compliant parallel manipulators (CPMs) including 3-DOF translational CPMs and 6-DOF CPMs using a building block based pseudo-rigid-body-model (PRBM) approach. The proposed multi-DOF CPMs are composed of wire-beam based compliant mechanisms (WBBCMs) as distributed-compliance compliant building blocks (CBBs). Firstly, a comprehensive literature review for the design approaches of compliant mechanisms is conducted, and a building block based PRBM is then presented, which replaces the traditional kinematic sub-chain with an appropriate multi-DOF CBB. In order to obtain the decoupled 3-DOF translational CPMs (XYZ CPMs), two classes of kinematically decoupled 3-PPPR (P: prismatic joint, R: revolute joint) translational parallel mechanisms (TPMs) and 3-PPPRR TPMs are identified based on the type synthesis of rigid-body parallel mechanisms, and WBBCMs as the associated CBBs are further designed. Via replacing the traditional actuated P joint and the traditional passive PPR/PPRR sub-chain in each leg of the 3-DOF TPM with the counterpart CBBs (i.e. WBBCMs), a number of decoupled XYZ CPMs are obtained by appropriate arrangements. In order to obtain the decoupled 6-DOF CPMs, an orthogonally-arranged decoupled 6-PSS (S: spherical joint) parallel mechanism is first identified, and then two example 6-DOF CPMs are proposed by the building block based PRBM method. It is shown that, among these designs, two types of monolithic XYZ CPM designs with extended life have been presented.

Building Block Based Topology Synthesis Algorithm to Optimize the Natural Frequency in Large Stroke Flexure Mechanisms

2020 ◽  
Author(s):  
Mathijs E. Fix ◽  
Dannis M. Brouwer ◽  
Ronald G. K. M. Aarts
Keyword(s):  
Natural Frequency ◽  
Building Block ◽  
Strain Energy ◽  
Natural Frequencies ◽  
Compliant Mechanisms ◽  
Large Range ◽  
Building Blocks ◽  
Synthesis Algorithm ◽  
Block Based ◽  
High Support

Abstract Flexure based compliant mechanisms suited for a large range of motion can be designed by handling the challenges arising from combining low compliance in the desired directions, high support stiffness, low stresses and high unwanted natural frequencies. Current topology optimization tools typically can’t model large deflections of flexures, are too conceptual or are case specific. In this research, a new spatial topological synthesis algorithm based on building blocks is proposed to optimize the performance of an initial design. The algorithm consists of successive shape optimizations and layout syntheses. In each shape optimization the dimensions for some layout are optimized. The layout synthesis strategically replaces the most “critical” building block with a better option. To maximize the first unwanted natural frequency the replacement strategy depends the strain energy distribution of the accompanying mode shape. The algorithm is tested for the design of a 1-DOF flexure hinge. The obtained final layout agrees with results known from literature.

scholarly journals Building block method: a bottom-up modular synthesis methodology for distributed compliant mechanisms

2012 ◽  
Vol 3 (1) ◽  
pp. 15-23 ◽  
Author(s):  
G. Krishnan ◽  
C. Kim ◽  
S. Kota
Keyword(s):  
Building Block ◽  
Compliant Mechanisms ◽  
Building Blocks ◽  
Load Flow ◽  
Optimization Techniques ◽  
Geometric Representation ◽  
Recent Developments ◽  
Block Based ◽  
Synthesis Methodology ◽  
Automated Optimization

Abstract. Synthesizing topologies of compliant mechanisms are based on rigid-link kinematic designs or completely automated optimization techniques. These designs yield mechanisms that match the kinematic specifications as a whole, but seldom yield user insight on how each constituent member contributes towards the overall mechanism performance. This paper reviews recent developments in building block based design of compliant mechanisms. A key aspect of such a methodology is formulating a representation of compliance at a (i) single unique point of interest in terms of geometric quantities such as ellipses and vectors, and (ii) relative compliance between distinct input(s) and output(s) in terms of load flow. This geometric representation provides a direct mapping between the mechanism geometry and their behavior, and is used to characterize simple deformable members that form a library of building blocks. The design space spanned by the building block library guides the decomposition of a given problem specification into tractable sub-problems that can be each solved from an entry in the library. The effectiveness of this geometric representation aids user insight in design, and enables discovery of trends and guidelines to obtain practical conceptual designs.

Thermoplastic building blocks for the fabrication of microfluidic masters

RSC Advances ◽  
2015 ◽  
Vol 5 (119) ◽  
pp. 97934-97943 ◽  
Author(s):  
Michael A. Stoller ◽  
Abhiteja Konda ◽  
Matthew A. Kottwitz ◽  
Stephen A. Morin
Keyword(s):  
Rapid Prototyping ◽  
Building Block ◽  
Building Blocks ◽  
Microfluidic Systems ◽  
Block Based

This manuscript reports a building-block-based approach for the design and fabrication of masters that enables “ultra-rapid” prototyping of functional microfluidic systems.

scholarly journals Building Block-Based Synthesis and Intensification of Work-Heat Exchanger Networks (WHENS)

Processes ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 23 ◽  
Author(s):  
Jianping Li ◽  
Salih Emre Demirel ◽  
M. M. Faruque Hasan
Keyword(s):  
Heat Exchanger ◽  
Building Block ◽  
Building Blocks ◽  
Mixed Integer ◽  
Total Annual Cost ◽  
Heat Integration ◽  
Design Element ◽  
Heat Exchanger Networks ◽  
Block Based ◽  
Energy Chain

We provide a new method to represent all potential flowsheet configurations for the superstructure-based simultaneous synthesis of work and heat exchanger networks (WHENS). The new representation is based on only two fundamental elements of abstract building blocks. The first design element is the block interior that is used to represent splitting, mixing, utility cooling, and utility heating of individual streams. The second design element is the shared boundaries between adjacent blocks that permit inter-stream heat and work transfer and integration. A semi-restricted boundary represents expansion/compression of streams connected to either common (integrated) or dedicated (utility) shafts. A completely restricted boundary with a temperature gradient across it represents inter-stream heat integration. The blocks interact with each other via mass and energy flows through the boundaries when assembled in a two-dimensional grid-like superstructure. Through observation and examples from literature, we illustrate that our building block-based WHENS superstructure contains numerous candidate flowsheet configurations for simultaneous heat and work integration. This approach does not require the specification of work and heat integration stages. Intensified designs, such as multi-stream heat exchangers with varying pressures, are also included. We formulate a mixed-integer non-linear (MINLP) optimization model for WHENS with minimum total annual cost and demonstrate the capability of the proposed synthesis approach through a case study on liquefied energy chain. The concept of building blocks is found to be general enough to be used in possible discovery of non-intuitive process flowsheets involving heat and work exchangers.

Kinematic Synthesis of Planar, Shape-Changing Rigid-Body Mechanisms With Prismatic Joints

2011 ◽  
Author(s):  
Kai Zhao ◽  
James P. Schmiedeler ◽  
Andrew P. Murray
Keyword(s):  
Rigid Body ◽  
Shape Change ◽  
Weighted Least Squares ◽  
Solution Space ◽  
Building Blocks ◽  
Optimization Method ◽  
Basic Block ◽  
Closed Curves ◽  
Revolute Joints ◽  
Prismatic Joints

This paper presents a procedure to synthesize planar rigid-body mechanisms, containing both prismatic and revolute joints, capable of approximating a shape change defined by a set of morphing curves in different positions. With the introduction of prismatic joints, the existing mechanization process needs to be revisited via a building-block approach. The basic block is the Assur group of class II, and the auxiliary block is a fourbar mechanism, crank slider or binary link. To approximate shape changes defined by both open and closed curves, a single degree-of-freedom (DOF) mechanism is generated by assembling these building blocks. In the case of a large number of morphing curves, a weighted least squares approach is applied to determine center point locations for revolute joints and sliding paths for prismatic joints in individual building blocks. Then, the building blocks are located in an assembly position to regenerate the morphing chain using a numerical optimization method. Because of the additional constraints associated with prismatic joints compared to revolute joints, the size of the solution space is reduced, so random searches of the design space to find solution mechanisms are ineffective. A genetic algorithm is employed here instead to find a group of viable designs within reasonable computational limits. The procedure is demonstrated with synthesis examples of two 1-DOF mechanisms, one approximating five open-curve profiles and the other four closed-curve profiles.

Thienopyrrolocarbazoles: New Building Blocks for Functional Organic Materials

2019 ◽  
Author(s):  
Dorian Bader ◽  
Johannes Fröhlich ◽  
Paul Kautny
Keyword(s):  
Building Block ◽  
Organic Materials ◽  
Building Blocks ◽  
Molecular Properties ◽  
The Family ◽  
Facile Preparation

The facile preparation of three regioisomeric thienopyrrolocarbazoles applying a convenient C-H activation approach is presented. Derived from indolo[3,2,1-<i>jk</i>]carbazole, the incorporation of thiophene into the triarylamine framework significantly impacted the molecular properties of the parent scaffold. The developed thienopyrrolocarbazoles enrich the family of triarylamine donors and constitute a novel building block for functional organic materials.

Thienopyrrolocarbazoles: New Building Blocks for Functional Organic Materials

2019 ◽  
Author(s):  
Dorian Bader ◽  
Johannes Fröhlich ◽  
Paul Kautny
Keyword(s):  
Building Block ◽  
Organic Materials ◽  
Building Blocks ◽  
Molecular Properties ◽  
The Family ◽  
Facile Preparation

The facile preparation of three regioisomeric thienopyrrolocarbazoles applying a convenient C-H activation approach is presented. Derived from indolo[3,2,1-<i>jk</i>]carbazole, the incorporation of thiophene into the triarylamine framework significantly impacted the molecular properties of the parent scaffold. The developed thienopyrrolocarbazoles enrich the family of triarylamine donors and constitute a novel building block for functional organic materials.

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