A New Mistuning Form Existed in Periodic Structure-Force Mistuning

2012 ◽  
Vol 229-231 ◽  
pp. 377-381
Author(s):  
Ai Lun Wang ◽  
Jie Chen ◽  
Qian Jin Wang
Keyword(s):  
Periodic Structure ◽  
Vibration Mode ◽  
Structure Design ◽  
Engineering Practice ◽  
Characteristic Vibration ◽  
Natural Parameter ◽  
Mode Localization ◽  
Vibration Localization ◽  
Natural Characteristic ◽  
Design And Manufacture

The mistuning of periodic structure was generally considered to be natural parameter mistuning, such as stiffness mistuning, damping mistuning and mass mistuning. However, in engineering practice, there was another kind of mistuning—force mistuning. Based on a typical concentrated parameter model of periodic structure, the vibration characteristics, such as natural characteristic, vibration mode and vibration localization of periodic structure with different mistuning forms, were compared and analyzed. The results show that, as a new mistuning form, force mistuning won’t bring mode localization, while it could lead to vibration response localization. The results are very important for periodic structure design and manufacture.

A New Mistuning Form in Periodic Structure - Force Mistuning

2012 ◽  
Vol 562-564 ◽  
pp. 2092-2096 ◽  
Author(s):  
Guo Hui Yang ◽  
Ai Lun Wang ◽  
Xu Hui Cao
Keyword(s):  
Periodic Structure ◽  
Vibration Mode ◽  
Vibration Characteristics ◽  
Vibration Response ◽  
Engineering Practice ◽  
Characteristic Vibration ◽  
Natural Parameter ◽  
Mode Localization ◽  
Vibration Localization ◽  
Natural Characteristic

The mistuning of periodic structure was generally considered to be natural parameter mistuning, such as stiffness mistuning, damping mistuning and mass mistuning. However, in engineering practice, there was another kind of mistuning——force mistuning, which has not been studied yet. Based on a typical concentrated parameter model of periodic structure, the vibration characteristics, such as natural characteristic, vibration mode and vibration localization of periodic structure with different mistuning forms, were compared and analyzed. The results show that, as a new mistuning form, force mistuning won’t bring mode localization, while it could lead to vibration response localization

scholarly journals Design and manufacture of the novel drum worm pair

2020 ◽  
Vol 103 (4) ◽  
pp. 003685042098122
Author(s):  
Jingzi Zhang ◽  
Jin’ge Wang ◽  
Kai Wang
Keyword(s):  
Contact Stresses ◽  
Primary Objective ◽  
Structure Design ◽  
Worm Gear ◽  
The Novel ◽  
Bending Stress ◽  
Manufacturing Method ◽  
Design And Manufacture ◽  
Maximum Contact ◽  
Worm Drive

Although a significant amount of research on robot joint reducer was conducted, there are few systematic investigations on a novel joint reducer adopting inner worm-gear plane enveloping drum worm drive. To satisfy the development of modular robot joint, the primary objective of this paper was to systematically investigate the drum worm drive adopted in the novel joint reducer with integrated structure of drive, transmission, and support in the following aspects: meshing theory, design, analysis, and manufacture. According to the gear meshing theory, mechanical design method, classical mechanics, finite element method, and machining principle of virtual center distance, the systematic investigations around the drum worm pair applied in the novel joint reducer were conducted including the macro and micro meshing theory, structure design, mechanical and contact properties analyses, and manufacturing method. The novel joint reducer’s integrated structure was designed, and the drum worm pair’s mechanical and contact properties analyses were conducted, which showed: (1) the worm’s bending stress and deflection, worm-gear teeth’s shear stress and bending stress as well as the maximum contact stresses were all below their corresponding allowable values; (2) the maximum contact stresses appeared at the engage-in position of the worm pair opposing to the engaging-out position where the largest contact areas appeared. Then the manufacturing of drum worm’s spiral tooth was conducted via the modified 4-axis linkage CNC grinder according to the conjugate motion. Finally the novel joint reducer’s industrial prototype was assembled. The novel joint reducer with integrated structure of drive, transmission and support was designed and manufactured for the first time. The flowchart of design and manufacture of the reducer’s drum worm pair in this process was formulated, which provides a new insight on the research of joint reducers as well as other fields.

Hierarchical Nano/Micro-structured Surfaces with High Surface Area/Volume Ratios

2021 ◽  
pp. 1-36
Author(s):  
Ketki Lichade ◽  
Yizhou Jiang ◽  
Yayue Pan
Keyword(s):  
Surface Structure ◽  
Surface Area ◽  
Light Trapping ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Structure Design ◽  
Surface Structures ◽  
Structured Surfaces ◽  
Design And Manufacture

Abstract Recently, many studies have investigated additive manufacturing of hierarchical surfaces with high surface area/volume (SA/V) ratios, and their performance has been characterized for applications in next-generation functional devices. Despite recent advances, it remains challenging to design and manufacture high SA/V ratio structures with desired functionalities. In this study, we established the complex correlations among the SA/V ratio, surface structure geometry, functionality, and manufacturability in the Two-Photon Polymerization (TPP) process. Inspired by numerous natural structures, we proposed a 3-level hierarchical structure design along with the mathematical modeling of the SA/V ratio. Geometric and manufacturing constraints were modeled to create well-defined three-dimensional hierarchically structured surfaces with a high accuracy. A process flowchart was developed to design the proposed surface structures to achieve the target functionality, SA/V ratio, and geometric accuracy. Surfaces with varied SA/V ratios and hierarchy levels were designed and printed. The wettability and antireflection properties of the fabricated surfaces were characterized. It was observed that the wetting and antireflection properties of the 3-level design could be easily tailored by adjusting the design parameter settings and hierarchy levels. Furthermore, the proposed surface structure could change a naturally-hydrophilic surface to near-superhydrophobic. Geometrical light trapping effects were enabled and the antireflection property could be significantly enhanced (>80% less reflection) by the proposed hierarchical surface structures. Experimental results implied the great potential of the proposed surface structures for various applications such as microfluidics, optics, energy, and interfaces.

Vibration Localization in Band/Wheel Systems: Theory and Experiment

1993 ◽  
Author(s):  
A. A. N. Al-jawi ◽  
A. G. Ulsoy ◽  
Christophe Pierre
Keyword(s):  
Simple Model ◽  
Coupling Model ◽  
Complex Model ◽  
Translation Speed ◽  
Mode Localization ◽  
Vibration Localization ◽  
Natural Modes ◽  
Theoretical Predictions ◽  
Axially Moving Beams ◽  
Axially Moving

Abstract An investigation of the localization phenomenon in band/wheel systems is presented. The effects of tension disorder, interspan coupling, and translation speed on the confinement of the natural modes of free vibration are investigated both theoretically and experimentally. Two models of the band/wheel system dynamics are discussed; a simple model proposed by the authors [1] and a more complete model originally proposed by Wang and Mote [9]. The results obtained using the simple interspan coupling model reveal phenomena (i.e., eigenvalue crossings and veerings and associated mode localization) that are qualitatively similar to those featured by the more complex model of interspan coupling, thereby confirming the usefulness of the simple coupling model. The analytical predictions of the two models are validated by an experiment. A very good agreement between the experimental results and the theoretical ones for the simple model is observed. While both the experimental observations and the theoretical predictions show that a beating phenomenon takes place for ordered stationary and axially moving beams, beating is destroyed (indicating the occurrence of localization) when any small tension disorder is introduced especially for small interspan coupling (i.e., when localization is strongest).

Modal Analysis on the Simulation of the Missile Launchers Based on ABAQUS

2014 ◽  
Vol 716-717 ◽  
pp. 676-678
Author(s):  
Cong Huang ◽  
Yi Jiang ◽  
Heng Zhang
Keyword(s):  
Modal Analysis ◽  
Vibration Mode ◽  
Design And Manufacture

One of the inevitable problems in the missile launchers is vibration, which can lead to failure of missile launchers. The3D model of the missile launchers is created and the modal analysis is adopted by the ABAQUS. The results show that the missile launchers will have resonance. The vibration mode diagram of the missile launcher’s structure is analyzed and the weakness of the missile launchers was found. The theory for the missile launchers design and manufacture is provided.

Effect of Chemical Etching on Adhesively Bonded Aluminum AA6082

2007 ◽  
Vol 344 ◽  
pp. 669-676 ◽  
Author(s):  
C. Borsellino ◽  
G. Di Bella ◽  
V.F. Ruisi
Keyword(s):  
Chemical Etching ◽  
Adhesive Bonding ◽  
Structure Design ◽  
The Body ◽  
Adhesively Bonded ◽  
Intimate Contact ◽  
Aluminum Sheets ◽  
Design And Manufacture ◽  
Aluminum Substrates ◽  
Aluminum Surfaces

The efforts of new automotive industry are mainly directed towards the substitution of aluminum for steel in the body structure because the aluminum structures are lighter than traditional steel ones and meet the requirements, in terms of both vehicle design and manufacture. However, this substitution is not so automatic, but it is important to study the material properties and the structure design, focusing the attention on the methods of joining. Welding, typical technique to joint steel parts, is particularly difficult when applied on aluminum ones and then, in many cases, the adhesive bonding is preferred. To optimise the joint performances it is necessary to pre-treat the metal surface, not only to remove contaminants, but also to provide the intimate contact needed for the adhesive to successfully bond with the adherent surface. The mere cleaning of aluminum surfaces is not suitable for their bonding due to the oxide layer that naturally occurs on exposure to air so we need to apply a more effective treatment (mechanical or chemical etching) to increase the adhesion capability of the substrates. In this work different adhesive joint configurations (single lap) between aluminum substrates are studied. Two different resins are employed to evaluate the influence of the adhesive on the joint performances. Moreover the aluminum sheets are treated with a chemical etching with two different procedures.

Topological Optimization Design and Manufacture of Microactuator Based on the Nodal Density Method

2007 ◽  
Author(s):  
Zhen Li ◽  
Baoyuan Sun ◽  
Min Qian ◽  
Jun Zhang
Keyword(s):  
Conceptual Design ◽  
Strain Energy ◽  
Optimization Design ◽  
Optimization Method ◽  
Structure Design ◽  
Topological Optimization ◽  
Structural Function ◽  
Micro Actuator ◽  
Nodal Density ◽  
Design And Manufacture

In order to improve the situation that the design of microactuator is mostly based on the intuition and experience of researchers, the method of continuum topology optimization using the nodal density is introduced to the conceptual design of microactuator. This new method can ensure C0 continuity of density field in a fixed design domain. The ratio of mutual energy to strain energy of the mechanism is regarded as the objective function, where, the mutual energy and strain energy describe the kinematic function and structural function of microactuator respectively. The final configuration of microactuator is decided on the guide of conceptual design combined with the given working conditions. The finite element method is applied to analysis the transmission ratio and clamping force of microactuator. The prototype of the microactuator is fabricated by using micro-electroforming and SU-8 photolithography techniques and the displacement of the micro actuator is measured by using the stereo vision microscopy. The experimental results show that the properties of the micro actuator can satisfy the designing demands. This topological optimization method based on nodal density plays an important role in guiding the structure design of micro actuator.

Technology Development and Application of Asphalt Concrete Impervious Panel

2013 ◽  
Vol 671-674 ◽  
pp. 1928-1931
Author(s):  
Yong Ye ◽  
Lei Tan
Keyword(s):  
Porous Material ◽  
Asphalt Concrete ◽  
Technology Development ◽  
Structure Design ◽  
Hydraulic Structures ◽  
Practice Research ◽  
Engineering Practice ◽  
Mineral Filler ◽  
Research Results

Asphalt concrete is a viscoelastic multiphase porous material consisting of asphalt, aggregates and mineral filler. The composite has good flexibility, durability and impervious properties, usually as an impervious body of hydraulic structures. Technology characteristics of the asphalt concrete impervious panel is summarized and the key of the structure design is reviewed according to the specification. Combining with engineering practice, research results provide a useful reference for the technology development and application of asphalt concrete impervious panel.

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