Effects of convection in laser-guided transportation

2004 ◽  
Vol 218 (7) ◽  
pp. 775-782
Author(s):  
L Chen ◽  
Y Yan ◽  
R Zhang
Keyword(s):  
Laser Beam ◽  
Three Dimensional ◽  
Biological Research ◽  
Convection Flow ◽  
Direct Write ◽  
Laser Guidance ◽  
Element Analysis ◽  
Research Areas ◽  
Fea Model ◽  
Set Up

Weak focusing laser beams can guide micrometre-sized beads to direct-write two-dimensional patterns or three-dimensional structures. Applications based on laser guidance have been found in many fields including biological research areas. This paper discusses the effects of convection, which is the main disturbance during laser-guided transportation. The heat generated by optical absorption causes the convection flow, as observed in experiments. To investigate this convection flow, a finite element analysis (FEA) model was set up and computation under different heat load conditions was carried out. The results show that the convection flow velocity at the laser beam centre has a direct proportional relation to the incident power and varies with the position of the laser beam.

Effect of Residual Stress or Plastic Deformation History on Fatigue Life Simulation of Pipeline Dents

2018 ◽  
Author(s):  
Xian-Kui Zhu ◽  
Rick Wang
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Three Dimensional ◽  
Strain History ◽  
Deformation History ◽  
Stress Strain ◽  
Element Analysis ◽  
Fea Model

Mechanical dents often occur in transmission pipelines, and are recognized as one of major threats to pipeline integrity because of the potential fatigue failure due to cyclic pressures. With matured in-line-inspection (ILI) technology, mechanical dents can be identified from the ILI runs. Based on ILI measured dent profiles, finite element analysis (FEA) is commonly used to simulate stresses and strains in a dent, and to predict fatigue life of the dented pipeline. However, the dent profile defined by ILI data is a purely geometric shape without residual stresses nor plastic deformation history, and is different from its actual dent that contains residual stresses/strains due to dent creation and re-rounding. As a result, the FEA results of an ILI dent may not represent those of the actual dent, and may lead to inaccurate or incorrect results. To investigate the effect of residual stress or plastic deformation history on mechanics responses and fatigue life of an actual dent, three dent models are considered in this paper: (a) a true dent with residual stresses and dent formation history, (b) a purely geometric dent having the true dent profile with all stress/strain history removed from it, and (c) a purely geometric dent having an ILI defined dent profile with all stress/strain history removed from it. Using a three-dimensional FEA model, those three dents are simulated in the elastic-plastic conditions. The FEA results showed that the two geometric dents determine significantly different stresses and strains in comparison to those in the true dent, and overpredict the fatigue life or burst pressure of the true dent. On this basis, suggestions are made on how to use the ILI data to predict the dent fatigue life.

Bionic Lubrication System of Artificial Joints: System Design and Mechanics Simulation

2005 ◽  
Author(s):  
S. H. Su ◽  
J. H. Zhang ◽  
D. H. Tao
Keyword(s):  
Three Dimensional ◽  
Joint Capsule ◽  
The Body ◽  
Artificial Joint ◽  
Lubrication System ◽  
Wear Particles ◽  
Element Analysis ◽  
Artificial Joints ◽  
Fea Model ◽  
Capsule Thickness

A new structure of artificial joints with bionic joint capsule was proposed and designed to overcome the feedback of current prostheses that omitted many functions of lubricant and joint capsule. The new structure was composed of three components: therapeutic lubricant, artificial joints and artificial joint capsule. The lubricant sealed by capsule not only can reduce the wear of artificial joints but also can prohibit the wear particles leaking to the body liquid. So the unwilling reactions between the wear particles and liquid may be avoided completely. Meanwhile, a three-dimensional (3-D) finite element analysis (FEA) model was created for the bionic artificial joints with joint capsule. The effects of capsule thickness and the flexion angels on the stress values and distributions were discussed in detail.

Numerical Investigation on Suction Pile’s Holding Capacity Installed in Carbonate-Type Soils

2020 ◽  
Author(s):  
Jianchun Cao ◽  
Zhibin Zhong ◽  
Ashish Budhiraja
Keyword(s):  
Skin Friction ◽  
Three Dimensional ◽  
Sensitivity Study ◽  
Element Analysis ◽  
Low Level ◽  
Total Displacement ◽  
Fea Model ◽  
Displacement Vectors ◽  
Three Dimensional Finite Element ◽  
Different Levels

Abstract Suction piles have not been widely used in carbonate-type soils (i.e., muds/silts) because the pile skin frictions in this type of soils are only about 5% of that in normal clayey soils. The holding capacity of a suction pile installed in these types of soils may be affected by its lower friction. Moreover, pile designers have concerns not only on the development of the Reverse End Bearing (REB) but also on how long the REB can sustain. This paper presents the development of a three-Dimensional Finite Element Analysis (3D FEA) model and the analysis results to investigate the behavior of suction pile for different levels of skin frictions. Firstly, the FEA model is used to investigate the development of the Reverse End Bearing (REB) of a suction pile by assigning two different levels of pile external skin frictions, i.e., 5% and 100% (full skin friction). A vertical load is applied at the center of the pile top. Secondly, the FEA model is used to investigate the behavior of a suction pile for a very low level of pile skin friction (i.e., 5% skin friction). An inclined load with various load angles from horizontal is applied at the padeye (i.e., 16m below seabed). Thirdly, the load carrying (failure) mechanism has been checked by examining the total displacement vectors of soil masses around the pile. Fourthly, a sensitivity study is carried out to investigate the capacity of a suction pile for different usage factors of REB. Finally, suction pile design requirements for carbonate-type soils (i.e., low level of pile skin frictions) are recommended.

Linear Statics Analysis of the Connecting Rod of a Certain Type of Continuous Mill with Mechanics Properties

2012 ◽  
Vol 252 ◽  
pp. 98-101
Author(s):  
Chang Ping Zou ◽  
Xiao Feng Zhang ◽  
De Rong Cheng ◽  
Xu Zhi Lu
Keyword(s):  
Large Scale ◽  
Integrated Design ◽  
Continuous Mill ◽  
Connecting Rod ◽  
Analysis Software ◽  
Element Analysis ◽  
Fea Model ◽  
3D Fea ◽  
Set Up ◽  
3D Solid

The connecting rod of a certain type of continuous mill early produces crackle,cannot work,hindering the production.The authors are entrusted with the 3D Finite Element Analysis (FEA) of the connecting rod.On SUN workstation,utilizing the large scale Integrated-Design Engineering Analysis Software,I-DEAS,the authors have constructed accurate 3D solid model of the connecting rod,set up effective 3D FEA model,found the solution of several kinds of law of stress distribution and deformation,reached valuable conclusions.

Structural Integrity Assessment Criteria and Service Life Prediction of Cold Wrinklebends

2012 ◽  
Author(s):  
Xian-Kui Zhu ◽  
Brian N. Leis
Keyword(s):  
Finite Element ◽  
Service Life ◽  
Structural Integrity ◽  
Pipeline Steel ◽  
Three Dimensional ◽  
Computation Time ◽  
Element Analysis ◽  
Integrity Assessment ◽  
Fea Model ◽  
Hardening Models

Three-dimensional elastic-plastic finite element analysis (FEA) is performed in this paper to simulate the complicated stresses and deformation of wrinklebends in a pipeline from its bending formation to operation under cyclic loading. Three plastic hardening models (isotropic, kinematic and combined isotropic/kinematic) are discussed and used in FEA of wrinklebend response that considers strain hardening and Bauschinger effects. The FEA simulation is carried out first for an elbow held at constant pressure while subject to cyclic bending, which serves as a benchmark case. The results show that the three hardening models lead to very different outcomes. Comparable FEA simulations are then developed for wrinklebends under cyclic pressure. Detailed parametric analysis is considered, including finite-element type, element sensitivity, computation time, and material input data. Based on those results viable nonlinear FEA model is developed as the basis to quantify wrinklebend response under service-like conditions. Based on the FEA results, fatigue damage is quantified using the Smith, Watson and Topper (SWT) parameter, and thereafter a damage criterion is proposed to predict the fatigue life of a wrinklebend under the pressure cycles of 72%–10% of SMYS for typical X42 pipeline steel. The results show that the wrinkle aspect ratio H/L is a key parameter to control the service life of a wrinklebend.

Self-Vibration Characteristics Analysis of the Yingzhou Bridge

2011 ◽  
Vol 90-93 ◽  
pp. 1212-1215 ◽  
Author(s):  
Yan Zeng ◽  
Zhi Yong Wang
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Element Analysis ◽  
Arch Bridge ◽  
Subspace Iteration ◽  
Characteristics Analysis ◽  
Set Up ◽  
Three Dimensional Finite Element ◽  
Main Bridge

In this paper dynamic behavior of the Ying Zhou main bridge in Luoyang is studied .The finite element analysis software ANSYS is adopted to set up three-dimensional finite element model of a CFT arch bridge of the main bridge .The natural periods and modes of the CFT arch bridge are calculated by using the subspace iteration method. Meanwhile its modal characteristics are analyzed. Some useful conclusions are got by the calculation and analysis of the bridge for the engineering construction.

Finite Element Modeling and Quantification of Mechanical Damage Severity in Pipelines

2016 ◽  
Author(s):  
Xian-Kui Zhu ◽  
Brian N. Leis
Keyword(s):  
Finite Element ◽  
Oil And Gas ◽  
Pipeline Steel ◽  
Three Dimensional ◽  
Mechanical Damage ◽  
Failure Behavior ◽  
Element Analysis ◽  
Fea Model ◽  
Transmission Pipeline ◽  
Element Type

Mechanical damage is one of the major threats to oil and gas transmission pipeline integrity, which has been the case now for decades. Although much work has been done in that context, due to the complexity of its effects mechanical damage severity remains difficult to quantify. Thus, work continues to better understand the failure mechanism and develop the means to screen damage severity. The present paper adopts a validated elastic-plastic finite element analysis (FEA) model to simulate mechanical dents in pipelines and to quantify the effects of damage through a broad parametric study. This considers the need for three-dimensional FEA models and the effects of FEA element type, soil constraint condition, indenter type, pipeline grade and initial pipe pressure on dent response. The FEA model is also used to assess the minimum wall thickness for which a dent has the minimal effect on pipeline integrity. Finally, application of the proposed FEA model is illustrated by successfully predicting the failure behavior of a dent in a full-scale fatigue test involving a modern pipeline steel.

Finite Element Optimization Design on the Back Frame of the Jaw Crusher PC5282

2012 ◽  
Vol 472-475 ◽  
pp. 2024-2028
Author(s):  
Sheng Guo ◽  
Wei Ping Huang ◽  
Nian Qing Guo
Keyword(s):  
Finite Element ◽  
Optimization Design ◽  
Static Load ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Jaw Crusher ◽  
Distribution Laws ◽  
Set Up

According to the main parameters of the jaw crusher PC5282, structure of the back frame was designed, and three-dimensional model of the back frame was also set up. Finite element analysis of the back frame under static load was done in COSMOSWORKS. The distribution laws of stress, displacement and deformation were revealed. Optimization design was also finished, and the weight of the back frame was reduced.

The Influence of Bolt Layout Form to the Dynamic Stiffness of the Column

2014 ◽  
Vol 577 ◽  
pp. 222-227
Author(s):  
Chen Shen ◽  
Zhong Ping Hua ◽  
Meng Sha Zhang ◽  
Zhou Zhang
Keyword(s):  
Natural Frequency ◽  
Dynamic Stiffness ◽  
Three Dimensional ◽  
Element Analysis ◽  
Three Dimensional Modeling ◽  
Lower Natural Frequency ◽  
Dimensional Modeling ◽  
Modeling Software ◽  
Set Up ◽  
Bolt Arrangement

In the case of the column materials to determined, the lower natural frequency of column is determined by the number of coupling bolts and bolt arrangement. In this paper, by three-dimensional modeling software of Solidwork column model of hobbing is set up, then by using ANSYS finite element analysis software. The initial four order natural frequency to the different number of connection bolts and the different arrangement of bolt are respectively calculated. After the initial four order natural frequency are contrasted, we conclude that in the case of merely considering dynamic stiffness this study reach it is the most reasonable to select 8-12 bolts in the hobbing of YKQ31300, and different bolt arrangement of effects on the dynamic stiffness of the column is very small and can be ignored.

Finite Element Analysis of Key Component on Two Wheels Scooter

2014 ◽  
Vol 597 ◽  
pp. 531-534
Author(s):  
Zhi Dong Huang ◽  
Yun Pu Du ◽  
Bao Quan Liu ◽  
Guang Yang ◽  
Yu Feng Liu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Strain Diagram ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Innovative Design ◽  
Driving System ◽  
Set Up

Based on Solidworks software, the three-dimensional model of two wheels scooter is set up. The finite element model of two wheels scooter is generated. Finite element analysis of driving system on two wheels scooter is investigated. The stress and strain of driving system is investigated. The stress diagram and the strain diagram are obtained. The method and the result can be used as a reference of innovative design of two wheels scooter.

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