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 Optimal design and experiment study of the double spherical rotor of the MSCSG

2021 ◽  
Vol 104 (1) ◽  
pp. 003685042199848
Author(s):  
Weijie Wang ◽  
Xiaocen Chen ◽  
Qiang Liu ◽  
Yahong Fan
Keyword(s):  
Finite Element ◽  
Degrees Of Freedom ◽  
Control Function ◽  
Dynamic Balance ◽  
Equivalent Stress ◽  
Mechanical Analysis ◽  
Magnetic Bearing ◽  
Maximum Equivalent Stress ◽  
And Control ◽  
Measurement And Control

The magnetically suspended control and sense gyroscope (MSCSG) integrates spacecraft attitude measurement and control function; this paper proposes a double spherical rotor (DSR) for MSCSG. The DSR realizes the five degrees of freedom (DOFs) full active control and full channel magnetic path decoupling by the following design: the spherical axial/radial reluctance magnetic bearings are adopted to control the 3DOFs translation of rotor in the range of double spherical envelope, Lorentz force magnetic bearing (LFMB) is used to precisely drive the 2DOFs universal deflection of rotor. The optimization model is established based on the structural mechanical analysis, taking the deviation between rotor centroid and shape center as the optimization objective, choosing the first order resonance frequency, maximum equivalent stress, rigid body displacement, polar moment of inertia and inertia ratio as constraints. Then the DSR is optimized and simulated by the finite element, the MSCSG principle prototype based on DSR is successfully developed, the online dynamic balance experiment and modal test of the DSR are conducted, where the vibration amount of the DSR decreases from 20 μm before the experiment to 0.14 μm after the experiment, which decreases by 99.3%, the first test modal is 2881 Hz which is 5% different from the finite element simulation value of 3034 Hz. The results show that the DSR has the good mechanical properties and magnetic circuit decoupling characteristics.

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.

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.

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.

BIOMECHANICAL STABILITY OF THE CERVICAL SPINE AFTER UNCINATE PROCESS RESECTION: A FINITE ELEMENT ANALYSIS

2015 ◽  
Vol 15 (06) ◽  
pp. 1540049 ◽  
Author(s):  
XUEFENG BO ◽  
XI MEI ◽  
HUI WANG ◽  
WEIDA WANG ◽  
ZAN CHEN ◽  
...  
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
Element Model ◽  
Uncinate Process ◽  
Total Deformation ◽  
Maximum Equivalent Stress ◽  
Left And Right ◽  
The Stability

When performing anterolateral foraminotomy for the treatment of cervical spondylotic radiculopathy, the extent of uncinate process resection affects the stability of the cervical spine. The aim of this study was to determine the stability of the cervical spine after resection of various amounts of the uncinate process. Based on computed tomography (CT) scans of an adult male volunteer, a three-dimensional geometric model of the cervical spine (C4-C6) was established using Mimics 13.1, SolidWorks 2012, and ANSYS 15.0 software packages. Next, the mechanical parameters of the tissues were assigned according to their different material characteristics. Using the tetrahedral mesh method, a three-dimensional finite element model of the cervical spine was then established. In modeling uncinated process resection, two excision protocols were compared. The first excision protocol, protocol A, mimicked the extent of resection used in current clinical surgical practice. The second excision protocol, protocol B, employed an optimal resection extent as predicted by the finite element model. Protocols A and B were then used to resect the left uncinate process of the C5 vertebra to either 50% or 60% of the total height of the uncinate process. The stability of the cervical spine was assessed by evaluating values of deformation and maximum equivalent stress during extension, flexion, lateral bending, and rotation. After protocol A resection, the total deformation was increased as was the maximum equivalent stress during left and right rotation. After protocol B resection, the total deformation was little changed and the maximum equivalent stress was visibly decreased during left and right rotation. As evidenced by these results, protocol B resection had relatively little effect on the stability of the cervical spine, suggesting that resection utilizing the limits proposed in protocol B appears to better maintain the stability of the cervical spine when compared with current clinical surgical practice as replicated in protocol A.

Design, Modeling and Finite Element Static Analysis of a New Two Axis Solar Tracker Using SolidWorks/COSMOSWorks

2013 ◽  
Vol 446-447 ◽  
pp. 738-743 ◽  
Author(s):  
Fateh Ferroudji ◽  
Toufik Ouattas ◽  
Chérif Khélifi
Keyword(s):  
Finite Element ◽  
Static Analysis ◽  
Safety Factor ◽  
Equivalent Stress ◽  
Maximum Displacement ◽  
3D Cad ◽  
Optimum Position ◽  
Maximum Equivalent Stress ◽  
Solar Tracker ◽  
The Stability

This paper presents the now design, modeling and static analysis of a new two-axis solar tracker (Azimuth and Altitude). The tracker is an electro-hydraulic device that keeps photovoltaic panels in an optimum position perpendicularly to the solar radiation during daylight hours. The tracker of 24 m² panel’s size was designed using the SolidWorks 3D CAD software. The finite element method (FEM) is adopted to ensure the stability and the reliability of the tracker. COSMOSWorks was used to determine displacement, equivalent stress and safety factor of the tracker under its own weight and wind load critical, namely wind speed of 130 km/h. Simulation results show that the maximum displacement of the structure is 1.18 mm, the level of the maximum equivalent stress is 74.43 MPa and the safety factor is about 3. The tracker structure completely satisfies the design requirements.

Semi-exact elastic solutions for thermo-mechanical analysis of functionally graded rotating disks

2011 ◽  
Vol 93 (12) ◽  
pp. 3239-3251 ◽  
Author(s):  
A. Hassani ◽  
M.H. Hojjati ◽  
G. Farrahi ◽  
R.A. Alashti
Keyword(s):  
Mechanical Analysis ◽  
Functionally Graded ◽  
Rotating Disks

Design Optimization for Double-T Root and Rim of Turbine Blade with Three-Dimensional Finite Element Method

2012 ◽  
Vol 215-216 ◽  
pp. 239-243
Author(s):  
Ming Hui Zhang ◽  
Di Zhang ◽  
Yong Hui Xie
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Design Optimization ◽  
Turbine Blade ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
Maximum Equivalent Stress ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Element Method

As the main bearing part in a turbine blade, the root carries most of the loads of the whole blade. The improvement of the root structure can be used to enhance the operation reliability of steam turbine. The research on design optimization for double-T root and rim of a turbine blade was conducted by three-dimensional finite element method. Based on the APDL (ANSYS parametric design language), a multi-variable parametric model of the double-T root and rim was established. Twelve characteristic geometrical variables of the root-rim were optimized to minimize the maximum equivalent stress. The optimal structure of the double-T root-rim is obtained through the optimization. Compared with the original structure, the equivalent stress level of the root and rim has a significant reduction. Specifically, the maximum equivalent stress of root and rim reduces by 14.25% and 13.59%, respectively.

Finite Element Analysis of Hydraulic Clipping Machine Shear Platform Dased on ANSYS

2014 ◽  
Vol 945-949 ◽  
pp. 190-193
Author(s):  
Hai Lin Wang ◽  
Yi Hua Sun ◽  
Ming Bo Li ◽  
Gao Lin ◽  
Yun Qi Feng ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Elastic Strain ◽  
Optimization Design ◽  
Equivalent Stress ◽  
Element Model ◽  
Element Analysis ◽  
Maximum Equivalent Stress

Q43Y-85D type crocodile hydraulic clipping machine was taken as research object to optimization design. A finite element model for clipping machine was built using shell unit as fundamental unit. ANSYS12.0 finite element method was used to analyze the deformation and stress distribution of the shear platform model of hydraulic clipping machine. The result showed that the maximum equivalent stress at the dangerous area was 368.162 MPa and the maximum elastic strain was 0.1814×10-2 mm. After the structural optimization design, it was found that the maximum equivalent stress decreased to 186.238 MPa which did not exceed the material’s yield limitation 215 MPa and the maximum elastic strain decreased to 0.919×10-3 mm which satisfied the requirement of stiffness.

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