Design and Bending Analysis of a Metamorphic Parallel Twisted-Scissor Mechanism

2021 ◽  
pp. 1-30
Author(s):  
Bhivraj Suthar ◽  
Seul Jung
Keyword(s):  
Real Life ◽  
Linear Displacement ◽  
Bending Stiffness ◽  
Bending Deformation ◽  
Robot Arms ◽  
Reconfigurable Robots ◽  
Linkage Design ◽  
Modern Engineering ◽  
Cantilever Bending ◽  
Scissor Mechanism

Abstract The conventional scissor mechanism is used in modern engineering and robotic applications due to its metamorphic ability. The folding configuration provides the space-saving and unfolding provides longer linear expansion capability. However, a conventional scissor suffers unexpected and uncontrolled large bending deformation due to low bending stiffness while unfolding configuration, which may damage its structure. It also has a sudden bending singularity during unfolding, which may also damage the actuator. These limitations impose a significant constraint on real-life applications such as foldable robot arms, space robot arms, reconfigurable robots, etc. In this paper, we proposed a multi-strands parallel twisted-scissor mechanism (PTSM) to enhance its usability. The PTSM is inspired by a rope structure and designed by introducing a metamorphic segment (MS) using the S-shape linkage design approach to improve its bending stiffness without affecting conventional scissors' fundamentals. The PTSM has a unique feature of several automatic-link locking mechanisms to avoid singularity without using additional sensors, mechanism, or control. We experimentally checked the proposed design's functionality and its feasibility. We formulated a cantilever bending model for foldable PTSM with N metamorphic segments considering revolute joint clearance for bending estimation, experimentally verified, and analyzed the bending deformation in the X-Y and Y-Z planes. Also, it is compared with a conventional scissor. Finally, we found that PTSM is stronger than conventional scissor and can fold/unfold smoothly using a single linear actuator. PTSM can provide large linear displacement with small bending deformation without bending singularity.

scholarly journals Prediction of steel resistance to stress corrosion cracking in seawater based on accelerated tests and structural studies

2019 ◽  
Vol 121 ◽  
pp. 04009
Author(s):  
Svetlana Mushnikova ◽  
Oleg Kharkov
Keyword(s):  
Structural Phase ◽  
Real Life ◽  
Austenitic Stainless Steels ◽  
Test Results ◽  
Mechanical Fracture ◽  
Bending Tests ◽  
Laboratory Test Results ◽  
Resistance To Stress ◽  
Concentrated Solution ◽  
Cantilever Bending

The paper presents the tests results of resistance of various structural steel classes to SCC in chloride solutions. The experiments were performed using cantilever bending tests developed by NRC “Kurchatov Institute” – CRISM “Prometey” with stepwise increasing load of Charpy-type precracking specimens. The criterion estimation of resistance to SCC when β = σSCC/σC > 0.85 was confirmed by the laboratory test results compared with the case studies of corrosion-mechanical fracture of shipbuilding structures in real life service conditions. A new approach of SCC susceptibility of austenitic stainless steels in marine conditions is proposed. It is based on estimation of the critical temperature of SCC when testing for SSRT in a concentrated solution of calcium chloride at temperatures from 20°C to 100°C. Specific features of the structural-phase composition of steels that detrimentally affect the resistance to SCC were discovered during the complex testing.

scholarly journals An Anisotropic Hyperelastic Constitutive Model with Bending Stiffness Interaction for Cord-Rubber Composites: Comparison of Simulation Results with Experimental Data

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Shulei Sun ◽  
Wenguo Chen
Keyword(s):  
Strain Energy ◽  
Tensile Deformation ◽  
Strain Energy Function ◽  
Deformation Energy ◽  
Bending Stiffness ◽  
Fiber Direction ◽  
Rubber Composites ◽  
Bending Deformation ◽  
Current Configuration ◽  
Nonsymmetric Stress

Based on the invariant theory of continuum mechanics by Spencer, the strain energy depends on deformation, fiber direction, and the gradients of the fiber direction in the deformed configuration. The resulting extended theory is very complicated and brings a nonsymmetric stress and couple stress. By introducing the gradient of fiber vector in the current configuration, the strain energy function can be decomposed into volumetric, isochoric, anisotropic, and bending deformation energy. Due to the particularity of bending deformation, the reinforced material has tensile deformation and compression deformation. The bending stiffness should be taken into consideration, and it is further verified by the bending simulation.

scholarly journals Integrating computer-aided engineering and computer-aided design for DNA assemblies

2020 ◽  
Author(s):  
Chao-Min Huang ◽  
Anjelica Kucinic ◽  
Joshua A. Johnson ◽  
Hai-Jun Su ◽  
Carlos E. Castro
Keyword(s):  
Computer Aided Design ◽  
Real Life ◽  
Structural Complexity ◽  
Computer Aided Engineering ◽  
Coarse Grained ◽  
Simulation Tools ◽  
Iterative Design ◽  
Modern Engineering ◽  
Computer Aided ◽  
Aided Design

AbstractFunctional properties of modern engineering products result from merging the geometry and material properties of underlying components into sophisticated overall assemblies. The foundation of this design process is an integration of computer aided design (CAD) tools that allow rapid geometric modifications with robust simulation tools to guide design iterations (i.e. computer-aided engineering, CAE). Recently, DNA has been used to make nanodevices for a myriad of applications across fields including medicine, nanomanufacturing, synthetic biology, biosensing, and biophysics. However, currently these self-assembled DNA nanodevices rely primarily on geometric design, and hence, they have not demonstrated the same sophistication as real-life products. We present an iterative design pipeline for DNA assemblies that integrates CAE based on coarse-grained molecular dynamics with a versatile CAD approach that combines top-down automation with bottom-up control over geometry. This intuitive framework redefines the scope of structural complexity and enhances mechanical and dynamic design of DNA assemblies.

FUNCTIONAL DECOMPOSITION — THE VALUE AND IMPLICATION FOR BOTH NEURAL NETWORKS AND DIGITAL DESIGNING

2006 ◽  
Vol 06 (01) ◽  
pp. 123-138 ◽  
Author(s):  
HENRY SELVARAJ ◽  
PIOTR SAPIECHA ◽  
MARIUSZ RAWSKI ◽  
TADEUSZ ŁUBA
Keyword(s):  
Synthesis Method ◽  
Real Life ◽  
Logic Synthesis ◽  
Decomposition Methods ◽  
Functional Decomposition ◽  
Data Dependencies ◽  
Sequential Machines ◽  
Vlsi Technology ◽  
Modern Engineering ◽  
Decision Tables

General functional decomposition is mainly perceived as a logic synthesis method for implementing Boolean functions into FPGA-based architectures. However it also has important applications in many other fields of modern engineering and science. In this paper, advantages of functional decomposition are demonstrated on "real life" examples. Application of decomposition-based methods in other fields of modern engineering is presented. In the case of decision tables, application of decomposition methods leads to significant benefits in the analysis process of data dependencies, especially in cases when the input decision tables are unmanageably large. Experimental results demonstrate that it can help implementing sequential machines using flip-flops or ROM memory. It also can be efficiently used as multilevel logic synthesis method for VLSI technology.

A peek in the micro-sized world: a review of design principles, engineering tools, and applications of engineered microbial community

2020 ◽  
Vol 48 (2) ◽  
pp. 399-409
Author(s):  
Baizhen Gao ◽  
Rushant Sabnis ◽  
Tommaso Costantini ◽  
Robert Jinkerson ◽  
Qing Sun
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Environmental Remediation ◽  
Real Life ◽  
Design Principles ◽  
Microbial Interactions ◽  
Potential Applications ◽  
New Gene ◽  
Global Biogeochemical Cycles ◽  
Synthetic Microbial Communities

Microbial communities drive diverse processes that impact nearly everything on this planet, from global biogeochemical cycles to human health. Harnessing the power of these microorganisms could provide solutions to many of the challenges that face society. However, naturally occurring microbial communities are not optimized for anthropogenic use. An emerging area of research is focusing on engineering synthetic microbial communities to carry out predefined functions. Microbial community engineers are applying design principles like top-down and bottom-up approaches to create synthetic microbial communities having a myriad of real-life applications in health care, disease prevention, and environmental remediation. Multiple genetic engineering tools and delivery approaches can be used to ‘knock-in' new gene functions into microbial communities. A systematic study of the microbial interactions, community assembling principles, and engineering tools are necessary for us to understand the microbial community and to better utilize them. Continued analysis and effort are required to further the current and potential applications of synthetic microbial communities.

The Speech-Language Pathologist in the Public Schools: Preparation for Real Life Practices From the Perspective of a Speech-Language Pathology Program Coordinator

2010 ◽  
Vol 11 (2) ◽  
pp. 60-65
Author(s):  
Francine Wenhardt
Keyword(s):  
Public Schools ◽  
School Setting ◽  
Real Life ◽  
Effective School ◽  
Program Coordinator ◽  
Educational Preparation ◽  
The Public ◽  
Speech Language Pathologist ◽  
New Graduate ◽  
Language Pathology

Abstract The speech-language pathologist (SLP) working in the public schools has a wide variety of tasks. Educational preparation is not all that is needed to be an effective school-based SLP. As a SLP currently working in the capacity of a program coordinator, the author describes the skills required to fulfill the job requirements and responsibilities of the SLP in the school setting and advises the new graduate regarding the interview process and beginning a career in the public schools.

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