Study on Optimization and FEM Analysis of Centrifugal Pump Body Structure

2010 ◽  
Vol 154-155 ◽  
pp. 1744-1747
Author(s):  
Lan Ying Wu ◽  
Yan Lin Wang
Keyword(s):  
Centrifugal Pump ◽  
Cell Size ◽  
Equivalent Stress ◽  
Grid Cell ◽  
Fem Analysis ◽  
Mechanical Equipment ◽  
Body Structure ◽  
Performance Requirements ◽  
Maximum Equivalent Stress ◽  
The Common

The centrifugal pump is the common mechanical equipment, which is extensively applied in the water conservancy, ships and other projects. In this paper, the centrifugal pump body structure was analyzed based on the actual working conditions, and the structure was also optimized. The research results show that the maximum equivalent stress of pump body structure is in the tongue, when the grid cell size is 6mm, the maximum equivalent stress is 36.843MPa; The maximum equivalent stress increases as the grid cell size decreases, and the unit number increases rapidly as the grid cell size decreases; When the wall thickness of pump is selected appropriately, the material can be saved about 6%, and the optimized structure of pump can be also meet the structural performance requirements.

scholarly journals An efficient optimization method for structures with local non-linearity

2016 ◽  
Vol 20 (suppl. 3) ◽  
pp. 879-886
Author(s):  
Zhao-Li Zheng ◽  
Yu-Qi Wang ◽  
Di Zhang
Keyword(s):  
Turbine Blade ◽  
Degrees Of Freedom ◽  
Fractal Theory ◽  
Linear Part ◽  
Equivalent Stress ◽  
Iteration Process ◽  
Optimization Method ◽  
Contact Model ◽  
Maximum Equivalent Stress ◽  
The Common

During the operation of turbines, one of the common accidents is due to the structure failure of blades. The contact model with strong non-linearity and time variation makes it difficult to be analyzed. In this paper, firstly, the contact model is described by using fractal theory. Secondly, the new method for the optimization of turbine blade is proposed, which is a kind of structure with local nonlinearity and multi degree of freedom. The method reduces the number of degrees of freedom by forming a new super element, which makes the linear part of turbine blade without repeated calculation in the non-linear iteration process. Therefore, it can shorten the calculation time and reduce the demand for computing resources. Finally, an optimization of the turbine blade is carried out, and the maximum equivalent stress reduces by 13.19%, which proves the effectiveness of the new optimization method.

Finite Element Analysis on the Blade Structure of Centrifugal Pump

2010 ◽  
Vol 154-155 ◽  
pp. 1748-1751
Author(s):  
Lan Ying Wu ◽  
Yan Lin Wang
Keyword(s):  
Stress Concentration ◽  
Fatigue Limit ◽  
Centrifugal Pump ◽  
Pressure Field ◽  
Stress And Strain ◽  
Mechanical Equipment ◽  
Element Analysis ◽  
Structure Surface ◽  
The Common ◽  
Water Conservancy

The centrifugal pump is the common mechanical equipment, which is extensively applied in the water conservancy, ships and other projects, and the blade structure is a very important part in the centrifugal pump. In this paper, the stress distribution and concentration of single blade in the impeller are analyzed under the different pressure field of the blade structure surface, and the fatigue failure of blade is also studied. The research results show that the we can get the stress and strain of the blade accurately and intuitively through the analysis for the blade structure, the stress concentration of the centrifugal pump blade is mainly in the root and junction of the wheel cover, and the import value of stress concentration is larger than the outlet; the stress concentration may be caused easily as the stress increases rapidly in the blade, which has a great impact on the fatigue strength, the fatigue limit of the blade with the stress concentration is decreased more obviously than the fatigue limit of the smooth blade.

scholarly journals Finite Element Modeling of Residual Stress at Joint Interface of Titanium Alloy and 17-4PH Stainless Steel

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 629
Author(s):  
Nana Kwabena Adomako ◽  
Sung Hoon Kim ◽  
Ji Hong Yoon ◽  
Se-Hwan Lee ◽  
Jeoung Han Kim
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Finite Element Modeling ◽  
Equivalent Stress ◽  
Stress Gradient ◽  
Joint Interface ◽  
Element Modeling ◽  
Actual Experiment ◽  
Maximum Equivalent Stress

Residual stress is a crucial element in determining the integrity of parts and lifetime of additively manufactured structures. In stainless steel and Ti-6Al-4V fabricated joints, residual stress causes cracking and delamination of the brittle intermetallic joint interface. Knowledge of the degree of residual stress at the joint interface is, therefore, important; however, the available information is limited owing to the joint’s brittle nature and its high failure susceptibility. In this study, the residual stress distribution during the deposition of 17-4PH stainless steel on Ti-6Al-4V alloy was predicted using Simufact additive software based on the finite element modeling technique. A sharp stress gradient was revealed at the joint interface, with compressive stress on the Ti-6Al-4V side and tensile stress on the 17-4PH side. This distribution is attributed to the large difference in the coefficients of thermal expansion of the two metals. The 17-4PH side exhibited maximum equivalent stress of 500 MPa, which was twice that of the Ti-6Al-4V side (240 MPa). This showed good correlation with the thermal residual stress calculations of the alloys. The thermal history predicted via simulation at the joint interface was within the temperature range of 368–477 °C and was highly congruent with that obtained in the actual experiment, approximately 300–450 °C. In the actual experiment, joint delamination occurred, ascribable to the residual stress accumulation and multiple additive manufacturing (AM) thermal cycles on the brittle FeTi and Fe2Ti intermetallic joint interface. The build deflected to the side at an angle of 0.708° after the simulation. This study could serve as a valid reference for engineers to understand the residual stress development in 17-4PH and Ti-6Al-4V joints fabricated with AM.

Effects of geographic information system vector–raster–vector data conversion on landscape indices

1996 ◽  
Vol 26 (8) ◽  
pp. 1416-1425 ◽  
Author(s):  
Pete Bettinger ◽  
Gay A. Bradshaw ◽  
George W. Weaver
Keyword(s):  
Information System ◽  
Fractal Dimension ◽  
Geographic Information System ◽  
Cell Size ◽  
Grid Cell ◽  
Conversion Process ◽  
Data Conversion ◽  
Edge Density ◽  
Gis Data ◽  
Landscape Level

The effects of geographic information system (GIS) data conversion on several polygon-and landscape-level indices were evaluated by using a GIS vegetation coverage from eastern Oregon, U.S.A. A vector–raster–vector conversion process was used to examine changes in GIS data. This process is widely used for data input (digital scanning of vector maps) and somewhat less widely used for data conversion (output of GIS data to specific formats). Most measures were sensitive to the grid cell size used in the conversion process. At the polygon level, using the conversion process with grid cell sizes of 3.05, 6.10, and 10 m produced relatively small changes to the original polygons in terms of ln(polygon area), ln(polygon perimeter), and 1/(fractal dimension). When grid cell size increased to 20 and 30 m, however, polygons were significantly different (p < 0.05) according to these polygon-level indices. At the landscape level, the number of polygons, polygon size coefficient of variation (CV), and edge density increased, while mean polygon size and an interspersion and juxtaposition index (IJI) decreased. The youngest and oldest age-class polygons followed the trends of overall landscape only in terms of number of polygons, mean polygon size, CV, and IJI. One major side effect of the conversion process was that many small polygons were produced in and around narrow areas of the original polygons. An alleviation process (referred to as the dissolving process) was used to dissolve the boundaries between similarly attributed polygons. When we used the dissolving process, the rate of change for landscape-level indices slowed; although the number of polygons and CV still increased with larger grid cell sizes, the increase was less than when the dissolving process was not used. Mean polygon size, edge density, and fractal dimension decreased after use of the dissolving process. Trends for the youngest and oldest age-class polygons were similar to those for the total landscape, except that IJI was greater for these age-classes than for the total landscape.

scholarly journals Numerical Simulation and Experimental Study on Axial Stiffness and Stress Deformation of the Braided Corrugated Hose

2021 ◽  
Vol 11 (10) ◽  
pp. 4709
Author(s):  
Dacheng Huang ◽  
Jianrun Zhang
Keyword(s):  
Numerical Simulation ◽  
Geometric Model ◽  
Equivalent Stress ◽  
Element Model ◽  
Maximum Error ◽  
Structural Features ◽  
Axial Stiffness ◽  
Frictional Stress ◽  
Maximum Equivalent Stress ◽  
Simulation Results

To explore the mechanical properties of the braided corrugated hose, the space curve parametric equation of the braided tube is deduced, specific to the structural features of the braided tube. On this basis, the equivalent braided tube model is proposed based on the same axial stiffness in order to improve the calculational efficiency. The geometric model and the Finite Element Model of the DN25 braided corrugated hose is established. The numerical simulation results are analyzed, and the distribution of the equivalent stress and frictional stress is discussed. The maximum equivalent stress of the braided corrugated hose occurs at the braided tube, with the value of 903MPa. The maximum equivalent stress of the bellows occurs at the area in contact with the braided tube, with the value of 314MPa. The maximum frictional stress between the bellows and the braided tube is 88.46MPa. The tensile experiment of the DN25 braided corrugated hose is performed. The simulation results are in good agreement with test data, with a maximum error of 9.4%, verifying the rationality of the model. The study is helpful to the research of the axial stiffness of the braided corrugated hose and provides the base for wear and life studies on the braided corrugated hose.

Design Optimization for Fir-Tree Root of Turbine Blade Considering Manufacturing Variations

2013 ◽  
Vol 694-697 ◽  
pp. 2733-2737
Author(s):  
Qin Zhou ◽  
Ming Hui Zhang ◽  
Hui Yong Chen ◽  
Yong Hui Xie
Keyword(s):  
Particle Swarm Optimization ◽  
Turbine Blade ◽  
Equivalent Stress ◽  
Particle Swarm ◽  
Pattern Search ◽  
Design System ◽  
Contact Method ◽  
Swarm Optimization ◽  
Maximum Equivalent Stress ◽  
Manufacturing Variation

An optimization design system for fir-tree root of turbine blade has been developed in this paper. In the system, a parametric model of the blade and rim was established based on the parametric design language APDL, and nonlinear contact method was used for analysis by ANSYS, meanwhile some optimization algorithms, such as Pattern Search Algorithm, Genetic Algorithm, Simulated Annealing Algorithm and Particle Swarm Optimization, were adopted to control the optimizing process. Five cases of manufacturing variation in contact surfaces between root and rim were taken into account, and the design objective was to minimize the maximum equivalent stress of root-rim by optimizing eight critical geometrical dimensions of the root and rim. As a result, the maximum equivalent stress of root-rim decreases markedly after the optimization in all cases. In consideration of both precision and computing time, particle swarm optimization is assessed as the best algorithm to solve structure optimization problem in this work. Corresponding to five different cases of manufacturing variation, the maximum equivalent stress of root and rim reduces by 7%, 8%; 27%, 24%; 27%, 22%; 25%, 19%; 10%, 14% using the Particle Swarm Optimization.

Optimization design of titanium alloy connecting rod based on structural topology optimization

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bin Zheng ◽  
Yi Cai ◽  
Kelun Tang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Topology Optimization ◽  
Optimization Design ◽  
Equivalent Stress ◽  
Connecting Rod ◽  
Element Analysis ◽  
Content Type ◽  
The Finite Element Analysis ◽  
Maximum Equivalent Stress

Purpose The purpose of this paper is to realize the lightweight of connecting rod and meet the requirements of low energy consumption and vibration. Based on the structural design of the original connecting rod, the finite element analysis was conducted to reduce the weight and increase the natural frequencies, so as to reduce materials consumption and improve the energy efficiency of internal combustion engine. Design/methodology/approach The finite element analysis, structural optimization design and topology optimization of the connecting rod are applied. Efficient hybrid method is deployed: static and modal analysis; and structure re-design of the connecting rod based on topology optimization. Findings After the optimization of the connecting rod, the weight is reduced from 1.7907 to 1.4875 kg, with a reduction of 16.93%. The maximum equivalent stress of the optimized connecting rod is 183.97 MPa and that of the original structure is 217.18 MPa, with the reduction of 15.62%. The first, second and third natural frequencies of the optimized connecting rod are increased by 8.89%, 8.85% and 11.09%, respectively. Through the finite element analysis and based on the lightweight, the maximum equivalent stress is reduced and the low-order natural frequency is increased. Originality/value This paper presents an optimization method on the connecting rod structure. Based on the statics and modal analysis of the connecting rod and combined with the topology optimization, the size of the connecting rod is improved, and the static and dynamic characteristics of the optimized connecting rod are improved.

Thermo-mechanical analysis and optimization of functionally graded rotating disks

2020 ◽  
Vol 55 (5-6) ◽  
pp. 159-171
Author(s):  
Hassan Mohamed Abdelalim Abdalla ◽  
Daniele Casagrande ◽  
Luciano Moro
Keyword(s):  
Finite Element ◽  
Equivalent Stress ◽  
Rotating Disk ◽  
Mechanical Analysis ◽  
Theory Of Elasticity ◽  
Functionally Graded ◽  
Rotating Disks ◽  
Maximum Equivalent Stress ◽  
Quadratic Programming Method ◽  
Stress Uniformity

The behavior of thermo-mechanical stresses in functionally graded axisymmetric rotating hollow disks with variable thickness is analyzed. The material is assumed to be functionally graded in the radial direction. First, a two-dimensional axisymmetric model of the functionally graded rotating disk is developed using the finite element method. Exact solutions for stresses are then obtained assuming that the plane theory of elasticity holds. These solutions are in accordance with finite element ones, thus showing the validity of the assumption. Finally, in order to reduce the maximum equivalent stress along the radius, the optimization of the material distribution is addressed. To avoid subsequent finite element simulations in the optimization process, which can be computationally demanding, a nonlinear constrained optimization problem is proposed, for which the solution is obtained numerically by the sequential quadratic programming method, showing prominent results in terms of equivalent stress uniformity.

scholarly journals Effects of Grid Cell Size in Altitude Control in an Augmented Reality Terrain Display

2020 ◽  
Author(s):  
David Da Silva Rosa ◽  
Johannes Ernst ◽  
Clark Borst ◽  
Marinus M. van Paassen ◽  
Max Mulder
Keyword(s):  
Augmented Reality ◽  
Cell Size ◽  
Grid Cell ◽  
Altitude Control

Investigation of Strength in G4-73 Type Centrifugal Fan Impeller

2011 ◽  
Vol 383-390 ◽  
pp. 5669-5673
Author(s):  
Song Ling Wang ◽  
Zhe Sun ◽  
Zheng Ren Wu
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Calculation Result ◽  
Working Condition ◽  
Equivalent Stress ◽  
Centrifugal Fan ◽  
The Finite Element Method ◽  
Total Displacement ◽  
Maximum Equivalent Stress

For the large centrifugal fan impeller, its working condition generally is bad, and its geometry generally is complex. So its displacements and stresses distribution are also complex. In this paper, we can obtain the fan impeller’s displacements and stresses distribution accurately through numerical simulation in G4-73 type centrifugal fan impeller using the finite element method software ANSYS. The calculation result shows that the maximum total displacement of the impeller is m, it occurs on the position of the half of the blade near the outlet of the impeller; and the maximum equivalent stress of the impeller is 193 MPa, it occurs on the contacted position of the blade and the shroud near inlet of the impeller. Furthermore, check the impeller strength, the result shows that the strength of the impeller can meet the requirement.

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