Early-Stage Analysis for MEMS Structural Optimization II: Its Application to Microrelay Reliability

2005 ◽  
Author(s):  
Koji Ishikawa ◽  
Takahiro Miki ◽  
Hiroki Mamiya ◽  
Q. Yu
Keyword(s):  
Structural Optimization ◽  
Mechanical Performance ◽  
Early Stage ◽  
Design Stage ◽  
Design Parameters ◽  
Total System ◽  
Concept Design ◽  
Restoring Force ◽  
Electrostatic Actuators ◽  
The Impact

This paper discusses a new structural optimization methodology for MEMS and its application to reliability evaluation of micro relays. Clarifying the relationship between system characteristics and design factors, our new design optimization method (called MESA) enables numerical evaluation of MEMS structures at the concept design stage. The relation is defined as sensitivity, which is calculated based on the system governing equations with an experimental method technique and a FEM analysis. The sensitivities show not only the effect of design parameters for the system performances but also the system tradeoffs. The MESA allows designers to obtain “rough” total system performance and create a new concept. The MESA is successfully applied to evaluate an electrostatic microrelay for DC/RF signal switching. With the aid of the MESA, we define existing problems of current cantilever-shape MEMS switches and propose new mechanical approaches in order to enhance the mechanical reliability. The MESA clearly shows us that there are tradeoffs in the switching phenomenon of cantilever microrelay. Based on the MESA information, a new switching concept, which has tri-state multi-finger lateral contacts, is established and the MEMS structure is designed and fabricated. The tri-state switching concept reduces the number of contacts and also disperses the impact energy, which aggravates adhesion. In addition, bi-electrostatic actuators increase the adverse force to prevent stiction without the increase of restoring force, which causes degradation or cracks of the contact surfaces. Furthermore, a new push-pull switching structure is designed as a second generation by means of the MESA. The MESA shows that the second concept will provide superior mechanical performance with keeping the high RF isolation.

Early-Stage Analysis for MEMS Structural Optimization I: Concept

2005 ◽  
Author(s):  
Takahiro Miki ◽  
Koji Ishikawa ◽  
Hiroki Mamiya ◽  
Qiang Yu
Keyword(s):  
Optimal Design ◽  
Early Stage ◽  
Design Method ◽  
Design Stage ◽  
Design Parameters ◽  
Total System ◽  
Trade Offs ◽  
Optimal Design Method ◽  
Stage Analysis ◽  
System Characteristics

We report on the development of a new micro-electro-mechanical systems (MEMS) optimal design method called MEMS Early-Stage Analysis (MESA), which supports the total system evaluation of MEMS devices before the design stage. Recently total system simulation and design using Computer Aided Engineering (CAE) analyses have become important in MEMS device development due to their fabrication and design complexity. Although a lot of CAE methods that can be applied to MEMS have been demonstrated, time-consuming trial-and-error processes are inevitable at the design stage in order to obtain an optimal structure. In our design method, we can clarify and simplify the relation between design parameters and the system characteristics using a MESA weighted orthogonal array. In the MESA array, the sensitivity of each design factor for the system performance shows numerically how the design parameter influences the system characteristics. The existent trade-offs between design parameters can be minimized by both modifying the design concept and adjusting the sensitivities. Therefore MEMS designers are able to optimize the total system based on the information from the MESA array. Moreover, particular system characteristics can be enhanced in order to meet the system requirement through the adjustment of weight values for the sensitivities. The MESA makes the evaluation of system validity possible at the concept design stage. To conduct the informative optimal design method at the beginning of development leads the reduction of the total MEMS design time and cost.

scholarly journals TOWARDS A VERIFICATION AND VALIDATING TESTING FRAMEWORK TO DEVELOP BESPOKE MEDICAL PRODUCTS IN RESEARCH-FUNDED PROJECTS

2021 ◽  
Vol 1 ◽  
pp. 3199-3208
Author(s):  
Emanuel Balzan ◽  
Pierre Vella ◽  
Philip Farrugia ◽  
Edward Abela ◽  
Glenn Cassar ◽  
...  
Keyword(s):  
Medical Devices ◽  
Early Stage ◽  
Design Stage ◽  
Concept Design ◽  
Proof Of Concept ◽  
Detailed Design ◽  
Testing Framework ◽  
Medical Products ◽  
Manufacturing Technologies ◽  
Validation Testing

AbstractResearch funded projects are often concerned with the development of proof-of-concept products. Consequently, activities related to verification and validation testing (VVT) are often not considered in depth, even though various design iterations are carried out to refine an idea. Furthermore, the introduction of additive manufacturing (AM) has facilitated, in particular, the development of bespoke medical products. End bespoke products, which will be used by relevant stakeholders (e.g. patients and clinicians) are fabricated with the same manufacturing technologies used during prototyping. As a result, the detailed design stage of products fabricated by AM is much shorter. Therefore, to improve the market-readiness of bespoke medical devices, testing must be integrated within the development from an early stage, allowing better planning of resources. To address these issues, in this paper, a comprehensive VVT framework is proposed for research projects, which lack a VVT infrastructure. The framework builds up on previous studies and methods utilised in industry to enable project key experts to capture risks as early as the concept design stage.

Fuzzy Sensitivity Analysis in the Context of Dimensional Management

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Thomas Oberleiter ◽  
Björn Heling ◽  
Benjamin Schleich ◽  
Kai Willner ◽  
Sandro Wartzack
Keyword(s):  
Tolerance Analysis ◽  
Design Stage ◽  
Special Focus ◽  
Total System ◽  
Early Design Stage ◽  
Technical Requirements ◽  
Geometric Deviations ◽  
Weak Points ◽  
Dimensional Management ◽  
The Impact

Real components always deviate from their ideal dimensions. This makes every component, even a serial production, unique. Although they look the same, differences can always be observed due to different scattering factors and variations in the manufacturing process. All these factors inevitably lead to parts that deviate from their ideal shape and, therefore, have different properties than the ideal component. Changing properties can lead to major problems or even failure during operation. It is necessary to specify the permitted deviations to ensure that every single product nevertheless meets its technical requirements. Furthermore, it is necessary to estimate the consequences of the permitted deviations, which is done via tolerance analysis. During this process, components are assembled virtually and varied with the uncertainties specified by the tolerances. A variation simulation is one opportunity to calculate these effects for geometric deviations. Since tolerance analysis enables engineers to identify weak points in an early design stage, it is important to know the contribution that every single tolerance has on a certain quality-relevant characteristic, to restrict or increase the correct tolerances. In this paper, a fuzzy-based method to calculate the sensitivity is introduced and compared with the commonly used extended Fourier amplitude sensitivity test (EFAST) method. Special focus of this work is the differentiation of the sensitivity for the total system and the sensitivities for the subsystems defined by the α-cuts of the fuzzy numbers. It discusses the impact of the number of evaluations and nonlinearity on sensitivity for EFAST and the fuzzy-based method.

Development of Representative Volume Element Homogenization Model for Predicting Transversely Isotropic Elasticity of Lithium-Ion Batteries

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Jin Chul Yun ◽  
Seong Jin Park
Keyword(s):  
Representative Volume Element ◽  
Lithium Ion ◽  
Transversely Isotropic ◽  
Volume Element ◽  
Elastic Behavior ◽  
Design Stage ◽  
Design Parameters ◽  
Concept Design ◽  
Representative Volume ◽  
Isotropic Elasticity

In this study, a representative volume element (RVE) homogenization approach is proposed to predict the mechanical properties of a lithium-ion battery (LIB) cell, module, and pack in an electric vehicle (EV). Different RVE models for the LIB jellyroll and module are suggested. Various elastic properties obtained from RVE analyses were compared to the analytic solution. To validate the approach suggested, the elastic responses of two types of homogenized LIB module for various loading cases were compared to the model where all the jellyroll and module components were described fully. Additionally, parametric studies were conducted to determine the relationship between design parameters of the jellyroll components and the elastic behavior of LIB jellyroll and module. The results obtained in this study provide useful information for both LIB cell developers, at the concept design stage, and engineers of electric vehicles who want to predict the mechanical safety of a battery pack.

Design for Fixturability (DFF) Methodology for Commodity Parts: A Case Study With Connecting Rod Designs

2002 ◽  
Vol 2 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Khurshid A. Qureshi ◽  
Kazuhiro Saitou
Keyword(s):  
Mass Production ◽  
Parametric Representation ◽  
Design Stage ◽  
Design Parameters ◽  
Concept Design ◽  
Connecting Rod ◽  
Automotive Engine ◽  
Part Families ◽  
Manufacturing Facilities

This paper presents a methodology called ‘Design for Fixturability’ (DFF). This methodology enables designers to perform manufacturability analysis of their product designs upfront into the design process. The DFF approach provides a mapping between parametric representation of a part design and fixturing capability of a facility and presents a methodology to evaluate the design with respect to the fixturing capabilities. The methodology is applicable to the mass-production commodity parts and part families, which typically require dedicated manufacturing facilities. A prototype DFF system for connecting rods of an automotive engine is developed. The system enables the designers to design the connecting rods by considering the fixturing (datums) capabilities of existing manufacturing facilities during the concept design stage, when design parameters are still not frozen. The DFF system analyzes the design with respect to fixturing capabilities of facilities and generates suggestions for the designer, to modify his design if required.

scholarly journals LCTC Ships Concept Design in the North Europe- Mediterranean Transport Scenario Focusing on Intact Stability Issues

2021 ◽  
Vol 9 (3) ◽  
pp. 278
Author(s):  
Germano Degan ◽  
Luca Braidotti ◽  
Alberto Marinò ◽  
Vittorio Bucci
Keyword(s):  
Design Stage ◽  
Strong Impact ◽  
Large Set ◽  
Concept Design ◽  
The North ◽  
Design Alternatives ◽  
Intact Stability ◽  
Multi Attribute Decision Making ◽  
Stability Issues ◽  
The Impact

In late years, the size of RoRo cargo ships has continuously increased, leading to the so-called Large Car Truck Carriers (LCTC). The design of these vessels introduced new challenges that shall be considered during the ship design since the conceptual stage, which has a very strong impact on the technical and economic performances of the vessel during all its life-cycle. In this work, the concept design of an LCTC is presented based on Multi-Attribute Decision Making (MADM). A large set of design alternatives have been generated and compared in order to find out the most promising feasible designs. The proposed approach is based on a Mathematical Design Model (MDM) capable to assess all the main technical and economic characteristics for each design. Among the others, here focus has been done on the ship stability to assure the compliance with statutory rules within the MDM. A new stability metamodel has been developed capable to define the cross curves of stability at the concept design stage. The proposed MADM methodology has been applied to North Europe-Mediterranean transport scenario highlighting the impact of main particulars describing hull geometry on the technical and economic performances of an LCTC ship.

scholarly journals Investigation and Statistical Modeling of the Mechanical Properties of Additively Manufactured Lattices

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3962
Author(s):  
Derek G. Spear ◽  
Anthony N. Palazotto
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Design Parameters ◽  
Statistical Experimental Design ◽  
Lattice Structures ◽  
Compression Tests ◽  
Static Compression ◽  
Interaction Terms ◽  
Cell Densities ◽  
The Impact

This paper describes the background, test methodology, and experimental results associated with the testing and analysis of quasi-static compression testing of additively manufactured open-cell lattice structures. The study aims to examine the effect of lattice topology, cell size, cell density, and surface thickness on the mechanical properties of lattice structures. Three lattice designs were chosen, the Diamond, I-WP, and Primitive Triply Periodic Minimal Surfaces (TPMSs). Uniaxial compression tests were conducted for every combination of the three lattice designs, three cell sizes, three cell densities, and three surface thicknesses. In order to perform an efficient experiment and gain the most information possible, a four-factor statistical experimental design was planned and followed throughout testing. A full four-factor statistical model was produced, along with a reduced interactions model, separating the model by the significance of each factor and interaction terms. The impact of each factor was analyzed and interpreted from the resulting data, and then conclusions were made about the effects of the design parameters on the resultant mechanical performance.

scholarly journals Sustainable early design exploration of mid-rise office buildings with different subsystems using comparative life cycle assessment

2021 ◽  
Author(s):  
Mohsen Zaker Esteghamati ◽  
Houri Sharifnia ◽  
Diep Ton ◽  
Patricia Asiatco ◽  
Georg Reichard ◽  
...  
Keyword(s):  
Life Cycle ◽  
Environmental Impacts ◽  
Sustainability Assessment ◽  
Office Buildings ◽  
Design Stage ◽  
Design Parameters ◽  
Design Exploration ◽  
Suitable Alternative ◽  
Early Design ◽  
The Impact

Minimizing environmental impacts over a building’s life cycle is critical to achieving sustainable communities. Early design is the most critical step to improve construction’s sustainability, as the majority of important decisions have not yet been made. However, the implementation of sustainability assessment in early design is data- and effort-intensive, resulting in limited whole building life cycle assessments. Previous studies have mainly focused either on single residential structures, included only a subset of building components, or investigated early design parameters mostly associated with energy efficiency. Whereas, comparison of alternative building subsystems at early design received less attention. This study aims to provide and utilize benchmark data for the life-cycle impacts of mid-rise office buildings, focusing on the impact of building subsystem selection at early design exploration. Environmental impacts were compared across six professionally-designed archetypes comprising compatible combinations of foundation, floor, and structural assemblies for a site in Charleston, South Carolina. Detailed operational energy modeling was performed using the EnergyPlus framework, where a range of code-compliant envelope systems are studied and paired with other assemblies. Lastly, sensitivity assessment and statistical analysis are performed to quantify uncertainty associated with the use of such data for early design guidance. The results suggest that decisions associated with the use phase (such as envelope selection) dominates life cycle impacts and should be prioritized. Additionally, no single subsystem governs all embodied impacts across different buildings. Lastly, it is critical to consider a large number of alternatives at the early design stage, as excluding a combination of subsystems might close pathways to reaching a more environmentally suitable alternative during design iterations/optimization.

Adaptive Preliminary-Design Workflow for Aero Engine Secondary Air System Cavities With an Application Case of Windage and Heat Transfer in a Rotor-Stator Cavity With Axial Through Flow

2018 ◽  
Author(s):  
Toni Wildow ◽  
Hubert Dengg ◽  
Klaus Höschler ◽  
Jonathan Sommerfeld
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Design Stage ◽  
Design Parameters ◽  
Preliminary Design ◽  
Geometry Model ◽  
Through Flow ◽  
Air System ◽  
Secondary Air ◽  
The Impact

At the preliminary design stage of the engine design process, the behaviour and efficiency of different engine designs are investigated and evaluated in order to find a best matching design for a set of engine objectives and requirements. The prediction of critical part temperatures as well as the reduction of the uncertainty of these predictions is decisive to bid a competitive technology in aerospace technology. Automated workflows and Design of Experiments (DOE) are widely used to investigate large number of designs and to find an optimized solution. Nowadays, technological progress in computational power as well as new strategies for data handling and management enables the implementation of large DOEs and multi-objective optimizations in less time, which also allows the consideration of more detailed investigations in early design stages. This paper describes an approach for a preliminary-design workflow that implements adaptive modelling and evaluation methods for cavities in the secondary air system (SAS). The starting point for the workflow is a parametric geometry model defining the rotating and static components. The flow network within the SAS is automatically recognized and CFD and Thermal-FE models are automatically generated using a library of generic models. Adaptive evaluation algorithms are developed and used to predict values for structural, air system and thermal behaviour. Furthermore, these models and evaluation techniques can be implemented in a DOE to investigate the impact of design parameters on the predicted values. The findings from the automated studies can be used to enhance the boundary conditions of actual design models in later design stages. A design investigation on a rotor-stator cavity with axial through flow has been undertaken using the proposed workflow to extract windage, flow field and heat transfer information from adiabatic CFD calculations for use in thermal modelling. A DOE has been set up to conduct a sensitivity analysis of the flow field properties and to identify the impact of the design parameters. Additionally, impacts on the distribution of the flow field parameters along the rotating surface are recognized, which offers a better prediction for local effects in the thermal FE model.

A COMPREHENSIVE APPROACH TO SURVIVABILITY ASSESSMENT IN NAVAL SHIP CONCEPT DESIGN

2021 ◽  
Vol 156 (A4) ◽  
Author(s):  
A S Piperakis ◽  
D J Andrews
Keyword(s):  
Design Process ◽  
Early Stage ◽  
Ship Design ◽  
Assessment Tools ◽  
Concept Design ◽  
Trade Offs ◽  
Assessment Approach ◽  
The Uk ◽  
Constituent Elements ◽  
The Impact

Alongside deploying weapons and sensors what makes a warship distinct is its survivability, being the measure that enables a warship to survive in a militarily hostile environment. The rising cost of warship procurement, coupled with declining defence budgets, has led to cost cutting, often aimed at aspects, such as survivability, which may be difficult to quantify in a manner that facilitates cost capability trade-offs. Therefore, to meet ever-reducing budgets, in real terms, innovation in both the design process and the design of individual ships is necessary, especially at the crucial early design stages. Computer technology can be utilised to exploit architecturally orientated preliminary design approaches, which have been conceived to explore innovation early in the ship design process and the impact of such issues as survivability. A number of survivability assessment tools currently exist; however, most fail to integrate all the constituent elements of survivability (i.e. susceptibility, vulnerability and recoverability), in that they are unable to balance between the component aspects of survivability. Some of these tools are qualitative and therefore less than ideal in specifying survivability requirements, others are aimed towards the more detailed design stages where implementing changes is heavily constrained or even impractical. This paper presents a survivability assessment approach combining various tools used by UCL and the UK Ministry of Defence, as well as a new approach for recoverability assessment. The proposed method attempts to better integrate and quantify survivability in early stage ship design, which is facilitated by the UCL derived, architecturally focused, design building block approach. The integrated survivability method is demonstrated for a set of naval combatant concept designs and for two replenishment ship studies to test the robustness of the proposed approach.

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