In-plane dynamic response of a hydraulic pipe subjected to random vibration

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wei Qu ◽  
Huailiang Zhang ◽  
Wei Li ◽  
Ling Peng ◽  
Wenqian Sun
Keyword(s):  
Random Vibration ◽  
Tunnel Boring Machine ◽  
Transmission Efficiency ◽  
Hydraulic Systems ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Characteristic Analysis ◽  
Content Type ◽  
Tunnel Boring ◽  
Selection Of

Purpose To improve the transmission efficiency and reduce the damage to pipes in the hydraulic systems of tunnel boring machine subjected to random vibration, this paper aims to propose a novel dynamic characteristic analysis method that considers random vibration. Design/methodology/approach A fluid-structure interaction motion equation of the pipe is established by using Hamilton’s principle. The finite element method and discrete analysis method of random vibration are used to construct a model of the dynamic behavior of the pipe. Findings The influences of fluid parameters and external excitation parameters on the dynamic characteristics of pipes are analyzed. The experimental results are found to be in good agreement with the simulation results, which demonstrates that the proposed analytical method can provide a theoretical reference for the design and selection of hydraulic pipes subjected to random vibration. Originality/value The proposed method can be regarded as a future calculation method for pipes subjected to random vibration, and the transmission efficiency of the pipe can be improved.

Offsite construction in the Australian low-rise residential buildings application levels and procurement options

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tong Lin ◽  
Sainan Lyu ◽  
Rebecca Jing Yang ◽  
Linda Tivendale
Keyword(s):  
Construction Industry ◽  
Design Methodology ◽  
Residential Buildings ◽  
Analysis Method ◽  
Structured Interviews ◽  
Content Type ◽  
High Rise ◽  
The World ◽  
Different Levels ◽  
Selection Of

PurposePrefabricated housing has become a boom industry across the world; however, the uptake of offsite construction (OSC) approaches in Australian low-rise buildings is rather low compared with high-rise buildings in other countries. This study aims to investigate and analyse the adoption of different levels of OSC approaches and the selection of different procurement options in Australian low-rise residential buildings.Design/methodology/approachThe research objectives were pursued through a mixed research method. An empirical questionnaire survey was carried out with 35 professionals in the Australian building and construction industry. Semi-structured interviews were conducted with 20 interviewees and analysed using thematic analysis method in NVivo software.FindingsThe research results found that the most suitable OSC level for Australian low-rise buildings is components-based prefabrication and identified the barriers to OSC uptake for each OSC level. The study also showed that the best option of procuring prefabricated products is from Australian manufacturers, followed by Australian suppliers/dealers and overseas manufacturers. Panelised prefabrication and components-based prefabrication are ranked as the most suitable OSC approaches for Australian manufacturers. Modular prefabrication is regarded as the most suitable for overseas manufacturer, while components-based prefabrication is the most suitable for Australian suppliers/dealers.Originality/valueThe selection of various OSC approaches and different procurement options in the low-rise residential buildings are scarcely explored topic, and thus, this study provides knowledge of interest for both researchers and practitioners.

SEGMENT CRACKS AND ALIGNMENT ISSUES FOR TUNNELING CONSTRUCTION

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Arulampalam Paul Suyanthiran
Keyword(s):  
Tunnel Boring Machine ◽  
Shield Tunnel ◽  
Proper Selection ◽  
Tunnel Boring ◽  
Twin Tunnel ◽  
Shield Tunnelling ◽  
Tunnel Alignment ◽  
Selection Of ◽  
Left Lead

This study describes the causes of shield tunnel segment cracks and alignment issues during shield tunnelling. The study was conducted in Down Town Line 3 (DTL3) contracts 926 and 927 twin tunnel projects in Singapore. It is revealed that these issues arose when Tunnel Boring Machine (TBM) shoving on curve alignment though TBM is designed with articulation, which allows the machines to handle tight curves with ease. The study focused on how construction methodology affects the quality of tunnelling in terms of alignment and segment cracks. It was found that the clearance between the tail shield and tunnel lining was not maintained during mining. As a result, the tail shield exerts stress on the segments and causes cracks. In addition, the tunnel alignment deviated from pre-designed alignment, which directly affects the safety and durability of the shield tunnel. This study concludes that a proper selection of ring type “right lead” or “left lead” and the appropriate key selection, along with the skill of the workers, significantly solve segment cracks and alignment issues.

Analysis of assembly defects in the cam curved groove mechanism

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Weibin Lan ◽  
Shouwen Fan ◽  
Shuai Fan
Keyword(s):  
Dynamic Characteristics ◽  
Contact Point ◽  
Contact Theory ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Interference Fit ◽  
Content Type ◽  
Cam Mechanism ◽  
Contact Points ◽  
General Mathematical Model

Purpose This paper aims to propose an elementary approach toward the identification of assembly defects of a cam curved groove mechanism. Design/methodology/approach A numerical analysis method for identifying the assembly defects of the cam curved groove mechanism is proposed by resorting to Hertz contact theory. A general mathematical model is established to analyze the kinematic and dynamic characteristics with an interference fit between the main roller and cam curved groove, including the contact points of the external and internal ring. Findings The analysis method of the contact point characteristics of the cam curved groove mechanism is given in this paper, and the kinematic and dynamic characteristics of the main roller can be analyzed. The numerical examples presented in this paper are implemented in MATLAB, feasibility and validity of the above algorithm are verified by the finite element method. Originality/value Regarding the defects of the interference fit, the findings of this paper can serve as a reference for researchers in reducing the defects in the design process of the cam mechanism.

scholarly journals The multi-objective optimization of tunneling boring machine control based on geological conditions identification

2020 ◽  
Vol 1 (1) ◽  
pp. 87-105
Author(s):  
Hongyuan Wang ◽  
Jingcheng Wang
Keyword(s):  
Objective Function ◽  
Nearest Neighbor ◽  
Tunnel Boring Machine ◽  
Geological Condition ◽  
Content Type ◽  
Multi Objective ◽  
Tunnel Boring ◽  
Geological Conditions ◽  
Optimization Control ◽  
Accuracy Of Prediction

PurposeThe purpose of this paper aims to design an optimization control for tunnel boring machine (TBM) based on geological identification. For unknown geological condition, the authors need to identify them before further optimization. For fully considering multiple crucial performance of TBM, the authors establish an optimization problem for TBM so that it can be adapted to varying geology. That is, TBM can operate optimally under corresponding geology, which is called geology-adaptability.Design/methodology/approachThis paper adopted k-nearest neighbor (KNN) algorithm with modification to identify geological conditions. The modification includes adjustment of weights in voting procedure and similarity distance measurement, which at suitable for engineering and enhance accuracy of prediction. The authors also design several key performances of TBM during operation, and built a multi-objective function. Further, the multi-objective function has been transformed into a single objective function by weighted-combination. The reformulated optimization was solved by genetic algorithm in the end.FindingsThis paper provides a support for decision-making in TBM control. Through proposed optimization control, the advance speed of TBM has been enhanced dramatically in each geological condition, compared with the results before optimizing. Meanwhile, other performances are acceptable and the method is verified by in situ data.Originality/valueThis paper fulfills an optimization control of TBM considering several key performances during excavating. The optimization is conducted under different geological conditions so that TBM has geological-adaptability.

scholarly journals A perspective of pipejacking works by tunnel boring machines in Hong Kong: part I – development, selection of design, operations and types of techniques

2021 ◽  
pp. 108-118
Author(s):  
Wilson W S Mok ◽  
Andrew S W Ng
Keyword(s):  
Hong Kong ◽  
Design Method ◽  
Tunnel Boring Machine ◽  
Tunnel Boring Machines ◽  
Tunnel Boring ◽  
Ground Conditions ◽  
History Of ◽  
Boring Machines ◽  
And Performance ◽  
Selection Of

In this paper, the history of pipejacking works by tunnel boring machines in Hong Kong, their development, selection of design method and tunnel boring machine (TBM), operations, length and alignment of a pipeline, types of techniques to suit different site constraints and ground conditions, and performance of the works are discussed. This paper should be read together with part II, which covers applications, problems encountered, cost and prospects.

The dynamic performance analysis of chevron shape textured hydrodynamic bearings

2019 ◽  
Vol 72 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Gourav Jamwal ◽  
Sanjay Sharma ◽  
R.K. Awasthi
Keyword(s):  
Reynolds Equation ◽  
Dynamic Performance ◽  
The Finite Element Method ◽  
Maximum Increase ◽  
Maximum Enhancement ◽  
Content Type ◽  
Texture Parameters ◽  
Dynamic Performance Analysis ◽  
Practical Implications ◽  
Selection Of

Purpose This paper aims to evaluate the various dynamic performance parameters of hydrodynamic journal bearings. For this, the bearing’s inner surface is textured with chevron-shaped textures with different texture depths and number of textures in different regions/locations. Design/methodology/approach In the present study, the effect of chevron-shaped texture having different values of texture depths, locations and number of textures has been numerically simulated. The dynamic performance characteristics have been calculated by solving the fluid flow governing Reynolds equation using the finite element method, assuming iso-viscous and Newtonian fluid. Findings The obtained results indicate that the bearing stability can be improved with the help of surface texture. Among all the investigated texture locations, the maximum increase in stability threshold speed is observed for fully textured distribution. Moreover, for the chevron-shaped texture considered in the present study, the optimum values of texture depth and number of textures have also been determined for maximum bearing stability. Practical implications While designing, designers should focus on those optimum values of texture depth, texture location and number of textures which lead to maximum enhancement in bearing stability. Originality/value This study is useful in the appropriate selection of chevron-shaped texture parameters on bearing surface for the maximum bearing stability.

Select the best supply chain by risk analysis for Indian industries environment using MCDM approaches

2017 ◽  
Vol 24 (5) ◽  
pp. 1400-1413 ◽  
Author(s):  
Mahesh Chand ◽  
Tilak Raj ◽  
Ravi Shankar ◽  
Aashish Agarwal
Keyword(s):  
Risk Management ◽  
Supply Chain ◽  
Risk Mitigation ◽  
Analysis Method ◽  
Rational Analysis ◽  
Content Type ◽  
Different Types ◽  
Network Process ◽  
Indian Industries ◽  
Selection Of

Purpose Risk management in supply chain (SC) is not an easy task due to different uncertainty and intricacy. Management of risk is necessary for smooth operation of SC. The purpose of this paper is to demonstrate multi-criteria decision-making (MCDM) approaches to select the best SC which has minimum risks. Design/methodology/approach In proposed methodologies different steps, i.e. goal, risk attributes, risk sub-attributes and alternatives are identified for the selection of best SC using analytical network process which is being followed by the Multi-Objective Optimization by Rational Analysis method. Findings Findings of this paper are highly valuable for Indian manufacturing industries for risk management in SC. It helps the researchers and managers to deal with different types of uncertainty and risks associated with SC. Research limitations/implications This research is limited only for risk management in SC. Other issues in SC can be analyzed and further extended by other MCDM approaches. Originality/value This paper identified the different risks in SC and a systematic way to find out the best SC which helps the researchers and managers in risk mitigation.

Transient Property Improvement of Hydraulic Cylinder Control for Tunnel Boring Machine Using Opposite Reference Filter

2020 ◽  
Vol 140 (3) ◽  
pp. 320-325
Author(s):  
Yoshihiro Ohnishi ◽  
Takahisa Shigematsu ◽  
Takuma Kawai ◽  
Shinichi Kawamura ◽  
Noboru Oda
Keyword(s):  
Tunnel Boring Machine ◽  
Hydraulic Cylinder ◽  
Tunnel Boring
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