Design method considering construction loads during shield tunneling using a three-dimensional FEM analysis model

2007 ◽  
pp. 515-520
Keyword(s):  
Design Method ◽  
Three Dimensional ◽  
Fem Analysis ◽  
Analysis Model ◽  
Shield Tunneling ◽  
Construction Loads

Fabrication of a piezoelectrically driven micropositioning 3-DOF stage with elastic body using a multi-material 3D printer

2020 ◽  
Vol 26 (9) ◽  
pp. 1579-1591
Author(s):  
Sang-Woo Baek ◽  
Nahm-Gyoo Cho ◽  
Dong-Hyeok Lee
Keyword(s):  
Elastic Body ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Fem Analysis ◽  
Experimental Results ◽  
Analysis Model ◽  
Content Type ◽  
Vision Measurement ◽  
Conventional Material ◽  
Single Material

Purpose This paper aims to propose a method for manufacturing multi-material monolithic structures with flexible materials to construct the elastic body by using a dual-nozzle three-dimensional printer to develop a piezoelectric (PZT)-driven micropositioning stage with three degrees of freedom (3-DOF) and flexure hinges. Design/methodology/approach Polylactic acid (PLA) and nylon were used for the lever structure’s frame and flexure hinge, respectively. Additionally, the stage consisted of three PZT actuators for fine movement in the nanometer scale in 3-DOF (x, y and θ-directions). For the design of the stage, the kinematic analysis model and the finite element method (FEM) analysis was undertaken for comparing between PLA with nylon (multi-material), PLA (single material) and aluminum (conventional-material). In addition, two verification experiments were implemented for the fabricated prototype stage. First, to evaluate various assessments (lever ratio, hysteresis, coupling error and resolution), a measurement is carried out using the three capacitive sensors. Then, a two-camera-vision measurement experiment was performed to verify the displacement and lever ratio over the full-scale working range of the fabricated positioning stage, and the results from the experimentation and the FEM analysis were compared. Findings The authors confirmed enhancements in the properties of the lever structure frame, which requires stiffness and of the hinge, which requires flexibility for elastic deformation. Comparing FEM analysis and experimental results, although the performance as shown by experimental results was lower: the maximum difference being 3.4% within the end-point working range; this difference was sufficient to be a plausible alternative for the aluminum-based stage. Originality/value Multi-material monolithic-structure fabrication has an effective advantage in improving the performance of the stage, by using a combination of materials capable of reinforcing the desired characteristics in the necessary parts. It was verified that the fabricated stage can substitute the aluminum-based stage and can achieve a higher performance than single-material stages. Thus, precise-positioning stages can be manufactured in many kinds of structures with various properties and contribute to weight reduction and low costs for application equipment.

An Experimental Study of Soft Rock Roadway with Anchored Support Structure Based on Nested Mechanical Analysis Model

2011 ◽  
Vol 90-93 ◽  
pp. 277-283
Author(s):  
Fu Sheng Liu ◽  
Gang Gang Dong ◽  
Su Hua Wang ◽  
Shao Jie Wang ◽  
Yang Song
Keyword(s):  
Design Method ◽  
Dynamic Pressure ◽  
Three Dimensional ◽  
Soft Rock ◽  
Mechanical Analysis ◽  
Analysis Model ◽  
Support Structure ◽  
Three Dimensional Finite Element ◽  
Soft Rock Roadway ◽  
Rock Roadway

This paper chooses anchored support engineering of ore dynamic pressure soft rock roadway Qinan, Huaibei city as an example, and with the help of nested mechanical analysis model of anchored support structure, the paper analyzes the range of elastoplasticity, the range of anchor note area, stress and displacement of original rocks of the reinforced project, and simulates three-dimensional finite element numerical and underwent engineering detection of the project. Practicality and validity of quantitative control design method of anchored support structure are proved by comparing the theoretic research, calculation results, and field measurement results.

New Groove Design and Three-Dimensional Numerical Simulation of Ultra-Fine Grain of Bar Rolling

2012 ◽  
Vol 581-582 ◽  
pp. 879-882
Author(s):  
Lei Cao ◽  
Xue Tong Li ◽  
Shu Jian Liu ◽  
Min Ting Wang
Keyword(s):  
Plastic Strain ◽  
Cross Section ◽  
Design Method ◽  
Three Dimensional ◽  
Rolling Process ◽  
Analysis Model ◽  
Bar Rolling ◽  
Groove Design ◽  
Fine Grain ◽  
Set Up

A new groove design method of uniform strong strain of bar rolling was proposed based on the principle of strong plastic deformation to manufacture ultra-fine grain(UFG), and flat-oval groove type with the characteristics of big crushed and multidirectional deformation was set up. The numerical analysis model of hot continuous bar rolling process was created using nonlinear finite element method. The study of the law of plastic strain distribution after each rolling pass of the caliber series indicated that the caliber can satisfy with the precise size and shape, and can also better introduce the plastic strain to the center of cross section and get uniform strong strain. The largest strain was more than 5.0 in the center of cross section, in which condition ultra-fine grain can be fabricated. Therefore, this study provides important theoretical basis for the ultra-fine grain of bar rolling development.

Study on construction loads during shield tunneling using a three-dimensional FEM model

2006 ◽  
Vol 21 (3-4) ◽  
pp. 250 ◽  
Author(s):  
Hitoshi Tajima ◽  
Masahiko Kishida ◽  
Naomitsu Fukai ◽  
Akihiro Dan ◽  
Masayuki Saito
Keyword(s):  
Three Dimensional ◽  
Shield Tunneling ◽  
Fem Model ◽  
Construction Loads

Modeling and experimental verification on directivity of an electret cell array loudspeaker

2012 ◽  
Vol 24 (3) ◽  
pp. 326-333 ◽  
Author(s):  
Yu-Chi Chen ◽  
Wen-Ching Ko ◽  
Han-Lung Chen ◽  
Hsu-Ching Liao ◽  
Wen-Jong Wu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Digital Control System ◽  
Analysis Model ◽  
Cell Array ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
The Finite Element Analysis ◽  
Directivity Characteristics

We propose a model to give us a method to investigate the characteristic three-dimensional directivity in an arbitrarily configured flexible electret-based loudspeaker. In recent years, novel electret loudspeakers have attracted much interest due to their being lightweight, paper thin, and possessing excellent mid- to high-frequency responses. Increasing or decreasing the directivity of an electret loudspeaker makes it excellent for adoption to many applications, especially for directing sound to a particular area or specific audio location. Herein, we detail a novel electret loudspeaker that possesses various directivities and is based on various structures of spacers instead of having to use multichannel amplifiers and a complicated digital control system. In order to study the directivity of an electret loudspeaker based on an array structure which can be adopted for various applications, the horizontal and vertical polar directivity characteristics as a function of frequency were simulated by a finite-element analysis model. To validate the finite-element analysis model, the beam pattern of the electret loudspeaker was measured in an anechoic room. Both the simulated and experimental results are detailed in this article to validate the various assertions related to the directivity of electret cell-based smart speakers.

scholarly journals A modular design method based on TRIZ and AD and its application to cutter changing robot

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110343
Author(s):  
Mei Yang ◽  
Yimin Xia ◽  
Lianhui Jia ◽  
Dujuan Wang ◽  
Zhiyong Ji
Keyword(s):  
Modular Design ◽  
Design Method ◽  
Idea Generation ◽  
Design Parameters ◽  
Problem Analysis ◽  
Concept Design ◽  
Functional Requirements ◽  
Shield Tunneling ◽  
Structural Hierarchy ◽  
And Performance

Modular design, Axiomatic design (AD) and Theory of inventive problem solving (TRIZ) have been increasingly popularized in concept design of modern mechanical product. Each method has their own advantages and drawbacks. The benefit of modular design is reducing the product design period, and AD has the capability of problem analysis, while TRIZ’s expertise is innovative idea generation. According to the complementarity of these three approaches, an innovative and systematic methodology is proposed to design big complex mechanical system. Firstly, the module partition is executed based on scenario decomposition. Then, the behavior attributes of modules are listed to find the design contradiction, including motion form, spatial constraints, and performance requirements. TRIZ tools are employed to deal with the contradictions between behavior attributes. The decomposition and mapping of functional requirements and design parameters are carried out to construct the structural hierarchy of each module. Then, modules are integrated considering the connections between each other. Finally, the operation steps in application scenario are designed in temporal and spatial dimensions. Design of cutter changing robot for shield tunneling machine is taken as an example to validate the feasibility and effectiveness of the proposed method.

scholarly journals Experimental & FEM Analysis of Orthodontic Mini-Implant Design on Primary Stability

2021 ◽  
Vol 11 (12) ◽  
pp. 5461
Author(s):  
Elmedin Mešić ◽  
Enis Muratović ◽  
Lejla Redžepagić-Vražalica ◽  
Nedim Pervan ◽  
Adis J. Muminović ◽  
...  
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Primary Stability ◽  
Fem Analysis ◽  
Implant Design ◽  
Special Focus ◽  
Engineering System ◽  
Mini Implants ◽  
Pull Out ◽  
Computer Aided

The main objective of this research is to establish a connection between orthodontic mini-implant design, pull-out force and primary stability by comparing two commercial mini-implants or temporary anchorage devices, Tomas®-pin and Perfect Anchor. Mini-implant geometric analysis and quantification of bone characteristics are performed, whereupon experimental in vitro pull-out test is conducted. With the use of the CATIA (Computer Aided Three-dimensional Interactive Application) CAD (Computer Aided Design)/CAM (Computer Aided Manufacturing)/CAE (Computer Aided Engineering) system, 3D (Three-dimensional) geometric models of mini-implants and bone segments are created. Afterwards, those same models are imported into Abaqus software, where finite element models are generated with a special focus on material properties, boundary conditions and interactions. FEM (Finite Element Method) analysis is used to simulate the pull-out test. Then, the results of the structural analysis are compared with the experimental results. The FEM analysis results contain information about maximum stresses on implant–bone system caused due to the pull-out force. It is determined that the core diameter of a screw thread and conicity are the main factors of the mini-implant design that have a direct impact on primary stability. Additionally, stresses generated on the Tomas®-pin model are lower than stresses on Perfect Anchor, even though Tomas®-pin endures greater pull-out forces, the implant system with implemented Tomas®-pin still represents a more stressed system due to the uniform distribution of stresses with bigger values.

Practitioner-friendly design method to improve the seismic performance of RC frame buildings

2021 ◽  
pp. 875529302098801
Author(s):  
Orlando Arroyo ◽  
Abbie Liel ◽  
Sergio Gutiérrez
Keyword(s):  
Seismic Performance ◽  
Design Method ◽  
Three Dimensional ◽  
Rc Frame ◽  
Structural System ◽  
Standard Code ◽  
Frame Buildings ◽  
Rc Frame Buildings ◽  
Mathematical Justification ◽  
Story Building

Reinforced concrete (RC) frame buildings are a widely used structural system around the world. These buildings are customarily designed through standard code-based procedures, which are well-suited to the workflow of design offices. However, these procedures typically do not aim for or achieve seismic performance higher than code minimum objectives. This article proposes a practical design method that improves the seismic performance of bare RC frame buildings, using only information available from elastic structural analysis conducted in standard code-based design. Four buildings were designed using the proposed method and the prescriptive approach of design codes, and their seismic performance is evaluated using three-dimensional nonlinear (fiber) models. The findings show that the seismic performance is improved with the proposed method, with reductions in the collapse fragility, higher deformation capacity, and greater overstrength. Furthermore, an economic analysis for a six-story building shows that these improvements come with only a 2% increase in the material bill, suggesting that the proposed method is compatible with current project budgets as well as design workflow. The authors also provide mathematical justification of the method.

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