Maturity assessment of the laminate variable stiffness design process

2017 ◽  
Vol 160 ◽  
pp. 804-812 ◽  
Author(s):  
Anthony Sabido ◽  
Luis Bahamonde ◽  
Ramy Harik ◽  
Michel J.L. van Tooren
Keyword(s):  
Design Process ◽  
Variable Stiffness ◽  
Maturity Assessment ◽  
Stiffness Design

Burgers viscoelastic model-based variable stiffness design of compliant clamping mechanism for leafy greens harvesting

2021 ◽  
Vol 208 ◽  
pp. 1-15
Author(s):  
Liangliang Zou ◽  
Jin Yuan ◽  
Xuemei Liu ◽  
Jinguang Li ◽  
Ping Zhang ◽  
...  
Keyword(s):  
Viscoelastic Model ◽  
Variable Stiffness ◽  
Leafy Greens ◽  
Model Based ◽  
Stiffness Design

Structural Analysis of Variable Stiffness Laminated Plates Using First-Order Shear Deformation Theory

2014 ◽  
Author(s):  
A. H. Akbarzadeh ◽  
M. Arian Nik ◽  
D. Pasini
Keyword(s):  
Transverse Shear ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
Variable Stiffness ◽  
Buckling Load ◽  
Shear Stresses ◽  
Critical Buckling Load ◽  
First Order ◽  
Stiffness Design ◽  
Transverse Shear Stresses

Constant and variable stiffness strategies have been developed to design a composite laminate. With the former, each layer is designed with straight fibers that have the highest stiffness and strength in the fiber direction. With the latter, on the other hand, the stiffness can change within each layer by placing the fibers along a curvilinear fiber path. A variable stiffness design results in improved structural performance, as well as opens up opportunities to search for trade-off among structural properties. During the manufacture of a variable stiffness design with Automated Fiber Placement, certain defects in the form of gaps and overlaps could appear within the laminate and affect the laminate performance. In this study, we use the first-order shear deformation theory to assess the effect of transverse shear stresses on the critical buckling load, free and forced vibration of a variable stiffness laminate with embedded defects, an issue so far rarely examined in literature. The governing differential equations for the static analysis are first derived. A semi-analytic solution is then obtained using the hybrid Fourier-Galerkin method and the numeric time integration technique. The eigenvalue analysis is also conducted to determine the fundamental frequency and critical buckling load of the plate. It is found that the behavior of a variable stiffness plate is much more affected by the shear stresses than a constant stiffness plate. Ignoring the effect of transverse shear stresses results in 34% error in the predicted buckling load of a variable stiffness laminate with overlaps and a length-to-thickness ratio of 10.

Continuous curvilinear variable stiffness design for improved strength of a panel with a cutout

2020 ◽  
pp. 1-9
Author(s):  
Sadben Khan ◽  
Mahdi Arian Nik ◽  
Kazem Fayazbakhsh ◽  
Zouheir Fawaz
Keyword(s):  
Variable Stiffness ◽  
Stiffness Design

scholarly journals Force-Dependent Bilinear Variable Stiffness Design of Continuum Structure.

2002 ◽  
Vol 68 (673) ◽  
pp. 1407-1412 ◽  
Author(s):  
Masao TANAKA ◽  
Masahiro TODOH ◽  
Akihisa NAOMI ◽  
Kazushige OKI
Keyword(s):  
Variable Stiffness ◽  
Stiffness Design ◽  
Continuum Structure

scholarly journals Curvilinear Variable Stiffness 3D Printing For Improved Mechanical Performance

2021 ◽  
Author(s):  
Sadben Khan
Keyword(s):  
3D Printing ◽  
Mechanical Performance ◽  
Variable Stiffness ◽  
Fused Filament Fabrication ◽  
Work Cell ◽  
Material Deposition ◽  
Stiffness Design ◽  
Open Hole ◽  
Line Scanner ◽  
Novel Design

<div>Continuous Curvilinear Variable Stiffness (CCVS) is proposed as a novel design technique to generate Variable Stiffness design for improving the performance of composite panels featuring open-hole cut-outs. Compared to existing VS design techniques, CCVS steers the fibers around the cut-out without breaking at the holes using only a single design variable the geometry. The technique utilises a numerical method known as Source Panel method, which is typically utilised in the fluid dynamics world. Utilising this technique, the performance of an open hole ASTM D5766 coupon manufactured using Fused Filament Fabrication (FFF) was improved 16-38% depending on the ratio of the hole to the width of the specimen. The technique was further</div><div>improved on to allow for arbitrary geometries such as fuselage cut-outs. A fuselage cut-out case was examined, and it was shown that a CCVS design can improve the performance over a QuasiIsotropic design by 57%. To validate CCVS, it is necessary to first manufacture and validate the part. This was done by developing a robotic 3D printing work-cell capable of 5 axis of material deposition of both thermoplastic and pre-impregnated carbon fiber. Finally, an in-process inspection technique was developed using a laser line scanner in the work-cell for the purposes of quality control. </div>

Bi-objective optimization design of material stiffness for improving contact interface performances

2020 ◽  
pp. 095440622097543
Author(s):  
Yicong Zhou ◽  
Qiyin Lin ◽  
Jun Hong ◽  
Nan Yang
Keyword(s):  
Contact Pressure ◽  
Contact Area ◽  
Optimization Design ◽  
Variable Stiffness ◽  
Contact Interface ◽  
Stiffness Optimization ◽  
Material Stiffness ◽  
Effective Contact ◽  
Stiffness Design ◽  
Distribution Uniformity

The characteristics of contact interfaces such as the distribution uniformity of the contact pressure and the effective contact area play a crucial role in engineering equipment. To investigate the influences of the variable material stiffness optimization (VMSO) design on the contact characteristics of the contact interfaces in an assembly, an heuristic-based VMSO algorithm is developed in this paper. A bi-objective function is defined by including both the distribution uniformity of the contact pressure and the effective contact area. A single bolted joint model is adopted as a design example. The results indicate that optimizing the stiffness of the materials around the contact interface is an effective approach to enhance the distribution uniformity of the contact pressure, increase the effective contact area and decrease the maximum contact pressure. Furthermore, the improvement effectiveness provided by the proposed variable stiffness design is better than that provided by the traditional variable thickness design.

A Tailor-Made Information Management Maturity Model for the European Central Bank (ECB)

2019 ◽  
pp. 1-33
Author(s):  
Beatriz Garcia Garrido ◽  
Paloma Beneito Arias
Keyword(s):  
Central Bank ◽  
Information Management ◽  
Design Process ◽  
European Central Bank ◽  
Maturity Model ◽  
Organizational Policies ◽  
Common Features ◽  
European Central ◽  
Maturity Assessment ◽  
Management Function

In 2011, the European Central Bank (ECB) developed a customized information management maturity model that was subsequently applied to assess the success of the implementation of the organizational policies, processes, and technologies supporting the information management function and to identify and priorities future activities. This chapter provides an overview of the model's objectives, design process, and principles and a comparison of the sources that were used to support its design. In addition, it provides a detailed description of the model's structure, including goals, key process areas and key practices, common features, and maturity levels. Furthermore, the chapter describes the process and the tools that the authors designed to support the maturity assessment and the results obtained during the first two applications of the model.

Review of the mechanical performance of variable stiffness design fiber-reinforced composites

2018 ◽  
Vol 25 (3) ◽  
pp. 425-437 ◽  
Author(s):  
Zhibo Xin ◽  
Yugang Duan ◽  
Wu Xu ◽  
Tianyu Zhang ◽  
Ben Wang
Keyword(s):  
Mechanical Performance ◽  
Variable Stiffness ◽  
Structure Design ◽  
Fiber Reinforced Composites ◽  
Basic Knowledge ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Reinforced Composite ◽  
Stiffness Design ◽  
Research Situation

Abstract Variable stiffness design (VSD) has been paid more attention for its capability of further exploiting the potential of fiber-reinforced composite in composite structure design. VSD under different mechanical property indexes is reviewed in this paper. The review mostly focuses on strength, buckling, frequency, and other more common mechanical indices. Subsequently, the usage of VSD method for several years is briefly summarized. Some successful tests about variable stiffness composite parts are introduced and the experiment results are also addressed. The article summarizes the research situation from both perspectives based on a number of papers about the VSD of composite materials in recent years and provides theoretical reference and basic knowledge to new researchers.

Micro-Spring’s Variable Stiffness Design and Characteristics Analysis

2015 ◽  
Vol 645-646 ◽  
pp. 830-835 ◽  
Author(s):  
Guo Hua Liu ◽  
Li Sui ◽  
Geng Chen Shi ◽  
Xu Hong Guo
Keyword(s):  
Variable Stiffness ◽  
Nonlinear Relationship ◽  
Complex Structures ◽  
Test Results ◽  
Machining Error ◽  
Stiffness Design ◽  
Characteristics Analysis ◽  
Design Idea ◽  
Simulation Results ◽  
Stretching Process

The variable stiffness micro-springs’ load and deformation have nonlinear relationship, thus they can be used in special occasions. MEMS processing technology can manufacture any complex structures in a plane, using this feature, a variable stiffness design idea for the planar micro-spring is proposed. That is, using one type of structure named contact pairs to achieve stiffness change during the micro-spring’s stretching process. Using contact pairs, two types of variable stiffness springs are designed: stiffness increase spring and stiffness convexity spring. Because of the influence of processing precision, the contact pairs’ sizes of the first type of variable stiffness spring are different each other, the machining error makes the test results and simulation results various. In order to avoid the above problem of above spring, this paper designs another two variable stiffness micro-springs, test results indicate that the improved variable stiffness springs can realize the variable stiffness’ tendency.

scholarly journals Variable stiffness design of redundantly actuated planar rotational parallel mechanisms

2017 ◽  
Vol 30 (2) ◽  
pp. 818-826 ◽  
Author(s):  
Kangkang Li ◽  
Hongzhou Jiang ◽  
Zuo Cui ◽  
Qun Huang
Keyword(s):  
Variable Stiffness ◽  
Parallel Mechanisms ◽  
Stiffness Design ◽  
Redundantly Actuated
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