scholarly journals Practical Structural Design Approach of Multiconfiguration Planar Single-Loop Metamorphic Mechanism with a Single Actuator

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Qiang Yang ◽  
Guangbo Hao ◽  
Shujun Li ◽  
Hongguang Wang ◽  
Haiyang Li
Keyword(s):  
Structural Design ◽  
Degrees Of Freedom ◽  
Design Method ◽  
Design Approach ◽  
Equivalent Resistance ◽  
Structural Synthesis ◽  
Single Loop ◽  
Metamorphic Mechanism ◽  
Resistance Matrix ◽  
Metamorphic Mechanisms

Abstract As a type of multiconfiguration mechanism that can operate in an under-actuated state, metamorphic mechanisms were proposed more than two decades ago and attracted significant interest. Studies on structural synthesis of metamorphic mechanisms tend to focus more on metamorphic techniques and the structural synthesis of source mechanisms for metamorphic mechanisms. By designing different constraint architectures of metamorphic joints, multistructures can be obtained from the same source metamorphic mechanism. To determine the constraint architectures of metamorphic joints and their different assembly combinations, a kinematic status matrix and a corresponding constraint status matrix are constructed based on the metamorphic cyclogram of a source mechanism. According to the equivalent resistance gradient model and the constraint status matrix, an equivalent resistance matrix for the metamorphic joints is proposed. A structural synthesis matrix of the metamorphic mechanism is then obtained from the equivalent resistance matrix by deducing the constraint form vectors of the metamorphic joints. Furthermore, a kinematic diagram synthesis of the source metamorphic mechanism of a planar single-loop metamorphic mechanism is proposed, which is based on only the 14 one- or zero-degrees-of-freedom linkage groups. The entire structural design method of a metamorphic mechanism is based on the structural synthesis matrix and is presented as a systematic process. Finally, the proposed structural design approach is illustrated by two examples to verify its feasibility and practicality. This study provides an effective method for designing a practical multi-mobility and multiconfiguration planar single-loop metamorphic mechanism with a single actuator.

Structure Synthesis of Multi-DOF Planar Metamorphic Mechanisms With a Single Driver

2020 ◽  
Author(s):  
Qiang Yang ◽  
Andrew P. Murray ◽  
David H. Myszka ◽  
Shujun Li
Keyword(s):  
Structural Design ◽  
Design Method ◽  
Degree Of Freedom ◽  
Source Mechanism ◽  
Equivalent Resistance ◽  
Structural Synthesis ◽  
Metamorphic Mechanism ◽  
Resistance Matrix ◽  
Kinematic Diagram ◽  
Metamorphic Mechanisms

Abstract This paper approaches the type synthesis of multi-degree of freedom planar metamorphic mechanisms with a single driver in a systematic process. The process is facilitated by implementing a constraint status matrix and a equivalent resistance matrix as a method for identifying an appropriate structure of planar metamorphic mechanisms with a single driver. Multi-structures can be obtained from the same source metamorphic mechanism by designing different constraint architectures of metamorphic joints. To determine the constraint architectures of metamorphic joints and their different assembly combinations, the constraint status matrix is built based on the task-based metamorphic cyclogram of a source mechanism. According to the equivalent resistance gradient model and the constraint status matrix, an equivalent resistance matrix for the metamorphic joints is proposed. A structural synthesis matrix of the metamorphic mechanism is then obtained from the equivalent resistance matrix by deducing the constraint-form vectors of the metamorphic joints. Furthermore, an effective kinematic diagram synthesis of the source mechanism of the planar metamorphic mechanism is proposed which is based only on the 14 one or zero degree-of-freedom (DOF) linkage groups. The entire structural design method of a metamorphic mechanism is based on the structural synthesis matrix and given in steps. Finally, a proposed structural design approach is illustrated by two examples.

scholarly journals Innovative design method of the metamorphic hand

2018 ◽  
Vol 15 (1) ◽  
pp. 172988141775415 ◽  
Author(s):  
Wei Sun ◽  
Jianyi Kong ◽  
Xingdong Wang ◽  
Huaiguang Liu
Keyword(s):  
Design Method ◽  
Kinematic Chain ◽  
Theoretical Method ◽  
Combination Method ◽  
Structural Synthesis ◽  
Innovative Design ◽  
Automated Production ◽  
Metamorphic Mechanism ◽  
Physical Experiments ◽  
Number Synthesis

In order to solve the last centimeter problem of automated production, it is necessary to innovative design of flexible fixture. This article presents a metamorphic hand design method through the principle of metamorphic mechanism. Firstly, kinematic chain satisfying the requirements is obtained by number synthesis and structural synthesis. Then, the kinematic chain becomes a mechanism that meets the requirements using regeneration design rules. And the holographic matrix description method is used to describe the configuration transformation of the metamorphic mechanism. Furthermore, through the combination method of kinematic chain, the metamorphic clamp increases the two joint fingers into a metamorphic hand. Finally, the validity of the theoretical method is verified by physical experiments.

Optimization for Vibration Reduction in Final Phase of Automotive Body Structural Design

2001 ◽  
Author(s):  
Yasuaki Tsurumi ◽  
Toshiaki Nakagawa ◽  
Nobuyuki Mori ◽  
Hiroshi Yamakawa
Keyword(s):  
Structural Design ◽  
Degrees Of Freedom ◽  
Large Scale ◽  
Design Method ◽  
Element Model ◽  
Performance Criteria ◽  
Scale Model ◽  
Automotive Body ◽  
Large Scale Model ◽  
Noise Vibration

Abstract In automotive body structural design, Computer Aided Engineering (CAE) has been widely used in order to evaluate noise, vibration, harshness (NVH). A CAE engineer has usually used a large-scale finite element model exceeding 1 million degrees of freedom to improve NVH performance criteria in the final design phase. It is, however, difficult for a CAE engineer to propose the modification candidate for the NVH reduction to an automotive designer in the phase, while good accuracy of the analysis is obtained by using the large-scale model. Only the small modifications can be performed for the NVH performance since configurations of main frame structures are usually determined with respect to crashworthiness in the phase. Therefore, a CAE engineer cannot provide the designer with effective information on time. In this paper, a new optimal design method using a reduction scheme based on the physical coordinates under many design constraints regarding the crashworthiness is proposed in order to overcome above problems. Our proposed method finds out an optimal layout and stiffness value efficiently from the calculation results of the large-scale model. That is, we determine the appropriate location and additional scalar spring constants by minimizing the acceleration of the observation grid. The effectiveness and availability of this method are confirmed using an example.

Analysis Method of Screw Algebra for Motion Characteristics of a 4-URU Parallel Metamorphic Mechanism

2013 ◽  
Vol 753-755 ◽  
pp. 2062-2065
Author(s):  
Zhong Hai Zhang ◽  
Duan Ling Li ◽  
Chun Xia Li
Keyword(s):  
Adjacency Matrix ◽  
Degrees Of Freedom ◽  
Linear Equations ◽  
Homogeneous System ◽  
Basic Solution ◽  
Moving Platforms ◽  
Metamorphic Mechanism ◽  
Screw Motions ◽  
Motion Characteristics ◽  
Metamorphic Mechanisms

A new 4-URU parallel metamorphic mechanism is proposed. A new method using screw adjacency matrix to describe the structural transformation of metamorphic mechanisms is put forward. This method overcomes the limitations of existing topological description method which cannot analyze the metamorphic mechanisms spatial structures and motion characteristics. Then the screw algebra method for analyzing the metamorphic mechanisms motion characteristics is introduced in detail. Firstly, screw motions homogeneous system of linear equations is determined by the screw adjacency matrix. Then the equations basic solution system determines the anti-screw system. Finally calculate the moving platforms motion screw system. Thus the metamorphic mechanisms motion characteristics, such as spatial structure in different configurations, the number of components and joints, degrees of freedom are obtained.

Innovative Use of Profiled Steel Plates for Seismic Structural Performance

2005 ◽  
Vol 8 (3) ◽  
pp. 247-257 ◽  
Author(s):  
Y. Fukumoto ◽  
T. Takaku ◽  
T. Aoki ◽  
K. A. S. Susantha
Keyword(s):  
Numerical Analysis ◽  
Seismic Performance ◽  
Structural Design ◽  
Design Method ◽  
Steel Plates ◽  
Structural Performance ◽  
Cyclic Testing ◽  
Beam Columns ◽  
Bridge Bents ◽  
Hot Rolled

This paper presents the innovative use of hot-rolled thickness-tapered mill products, longitudinally profiled (LP) plates, for the seismic performance of bridge bents of single and portal framed piers. The study involves the inelastic cyclic testing and numerical analysis of tested beam-columns and portal frames in order to evaluate the effects of tapering ratios of LP plates, penetration of yielding, and number of locally buckled panels on their structural ductility. A structural design method is proposed for the portal frames having LP panels under cyclic loadings.

Design and Analysis of Motion Mechanism Driven by Several IDMs in Parallel

2012 ◽  
Vol 197 ◽  
pp. 55-59 ◽  
Author(s):  
Nan Jiang ◽  
Jun Biao Liu
Keyword(s):  
Degrees Of Freedom ◽  
Design Method ◽  
Piezo Actuator ◽  
Motion Mechanism ◽  
Spherical Motor ◽  
Drive Mechanism ◽  
Follow Up Study ◽  
Analysis Of Motion

As a kind of piezo actuator, impact drive mechanism (IDM) has advantages in precision machinery and instruments. Several IDMs are used in parallel to realize some motion mechanisms which have multi degrees of freedom (DOF). Two motion mechanisms are designed subsequently, and a spherical motor is designed and assembled in principle based on one of them. Experiment results reveal that this design method is feasible, but some problems exist, for example, vibration is serious. These problems should be solved in follow-up study.

AN OPTIMIZATION MODEL FOR PRELIMINARY STABILITY AND CONFIGURATION ANALYSES OF SEMI-SUBMERSIBLES

2021 ◽  
Vol 159 (A3) ◽  
Author(s):  
G D Gosain ◽  
R Sharma ◽  
Tae-wan Kim
Keyword(s):  
Optimization Model ◽  
Design Method ◽  
Optimization Techniques ◽  
Design Approach ◽  
Preliminary Design ◽  
Design Environment ◽  
Preliminary Stage ◽  
Steel Weight ◽  
Motion Characteristics ◽  
Almost All

In the modern era of design governed by economics and efficiency, the preliminary design of a semi-submersible is critically important because in an evolutionary design environment new designs evolve from the basic preliminary designs and the basic dimensions and configurations affect almost all the parameters related to the economics and efficiency (e.g. hydrodynamic response, stability, deck load and structural steel weight of the structure, etc.). The present paper is focused on exploring an optimum design method that aims not only at optimum motion characteristics but also optimum stability, manufacturing and operational efficiency. Our proposed method determines the most preferable optimum principal dimensions of a semi-submersible that satisfies the desired requirements for motion performance and stability at the preliminary stage of design. Our proposed design approach interlinks the mathematical design model with the global optimization techniques and this paper presents the preliminary design approach, the mathematical model of optimization. Finally, a real world design example of a semi-submersible is presented to show the applicability and efficiency of the proposed design optimization model at the preliminary stage of design.

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