Structural Design and Stress Analysis of a High-Speed Turbogenerator Assembly Supported by Hydrodynamic Bearings

Author(s):  
Rodrigo Teixeira Bento ◽  
André Ferrus Filho ◽  
Marco Antonio Fumagalli

Turbine and bushing bearing are the most critical components of high-speed machines. This article describes the design of a high-speed turbine supported by hydrodynamic bearings. The mathematical dimensioning and the FEM analysis are presented to validate the mechanical strength of the turbine and the bushing bearing models. Fatigue life and factor of safety were also determined. The simulations showed that the maximum Von Mises stress values obtained are associated to the centrifugal force generated by the system rotational movement. The results variation was mainly due to the properties of the materials proposed. For the turbine, 7075-T6 aluminum alloy and SAE 4340 steel obtained satisfactory behavior under a constant operating speed of 30,000 RPM. For the hydrodynamic bearing, the TM23 bronze alloy exhibited excellent results, without fracture, and low mechanical deformation. The models exhibited a great potential employment in several applications, such as biogas systems to generate electrical energy, and educational test bench for thermodynamic and tribological simulations.

2018 ◽  
Vol 180 ◽  
pp. 01005 ◽  
Author(s):  
Andrzej Wilk

Transmission of electrical energy from a catenary system to traction units must be safe and reliable especially for high speed trains. Modern pantographs have to meet these requirements. Pantographs are subjected to several forces acting on their structural elements. These forces come from pantograph drive, inertia forces, aerodynamic effects, vibration of traction units etc. Modern approach to static and dynamic analysis should take into account: mass distribution of particular parts, physical properties of used materials, kinematic joints character at mechanical nodes, nonlinear parameters of kinematic joints, defining different parametric waveforms of forces and torques, and numerical dynamic simulation coupled with FEM calculations. In this work methods for the formulation of the governing equations of motion are presented. Some of these methods are more suitable for automated computer implementation. The novel computer methods recommended for static and dynamic analysis of pantographs are presented. Possibilities of dynamic analysis using CAD and CAE computer software are described. Original results are also presented. Conclusions related to dynamic properties of pantographs are included. Chapter 2 presents the methods used for formulation of the equation of pantograph motion. Chapter 3 is devoted to modelling of forces in multibody systems. In chapter 4 the selected computer tools for dynamic analysis are described. Chapter 5 shows the possibility of FEM analysis coupled with dynamic simulation. In chapter 6 the summary of this work is presented.


2016 ◽  
Vol 2 (1) ◽  
pp. 20-25
Author(s):  
Michal Tropp ◽  
Michal Lukac

The article covers the usability of alternative materials in vehicle construction. The paper elaborates upon the setup of the process and analysis of the results of the carbon composite component FEM model. The 3D model, used for the examination, is a part of axle from an alternative small electric vehicle. The analysis was conducted with the help of MSC Adams and Ansys Workbench software. Color maps of von Mises stress in material and total deformations of the component are the results of calculation.


2021 ◽  
Vol 29 (2) ◽  
Author(s):  
Saddam Hussein Raheemah ◽  
Kareem Idan Fadheel ◽  
Qais Hussein Hassan ◽  
Ashham Mohammed Aned ◽  
Alaa Abdulazeez Turki Al-Taie ◽  
...  

The present study aims to investigate crack presence in a rigid steel beam so that it can be considered in structural design. A finite element method (FEM) had been used with the Ansys 16.1 software to simulate the whole steel body with three different forces and moments with a magnitude force subjected at the free end of the beam. The steel rod had been considered as simple cantilever to be modelled by the software. Von Mises stress had been considered in the simulation process where the maximum value of stress due to applied load and moment was 1.9 MPa. Total deformation of the whole body had also been considered to instigate the maximum deformation (4.3mm) due to applied loads and moments. Furthermore, MATLAB and through fuzzy logic had been used to assist in the investigation of cracks. Both approaches had been governed by the Euler-Bernoulli theory for free vibration of motion equations. The other aim of this study is to evaluate results received from the Ansys with MATLAB for the same boundary conditions as the case.


2020 ◽  
Vol 10 (22) ◽  
pp. 8121 ◽  
Author(s):  
Yi Zhao ◽  
Hong-Nan Li ◽  
Shuocheng Zhang ◽  
Oya Mercan ◽  
Caiyan Zhang

Seismic resilience of critical infrastructure, such as liquefied natural gas (LNG) storage tanks, is essential to the safety and economic well-being of the general public. This paper studies the effect of different ground motions on large LNG storage tanks under four different site conditions. Key parameters of structural design and dynamic analysis, including von Mises stress of outer and inner tanks, tip displacement, and base shear, are analyzed to directly evaluate the safety performance of the large LNG tanks. Because the size of an LNG tank is too large to perform any experiments on a physical prototype, Smoothed Particle Hydrodynamics-Finite Element Method (SPH-FEM) simulation is used as a feasible and efficient method to predict its seismic response. First, the accuracy of the SPH-FEM method is verified by comparing sloshing frequencies obtained from theoretical formulation to experimental results and SPH-FEM models. Then, the seismic response of a real-life 160,000 m3 LNG prestressed storage tank is evaluated with different liquid depths under four site classes. Simulation results show that the tip displacements of the LNG tank at liquid levels of 25% and 50% under site class IV are nearly identical to that of 75% and 100% under site class II. In addition, the maximum von Mises stress of the inner tanks exceeds 500 MPa in all four site classes and jeopardizes the structural integrity of large LNG tanks. As a result, optimization of structural design and the establishment of an early warning system are imperative to the safety of LNG tanks at high liquid levels.


2012 ◽  
Vol 157-158 ◽  
pp. 308-311
Author(s):  
Yong Ping Hao ◽  
Li Ya Bao ◽  
Shuang Xi Gu

In this paper, a novel MEMS inertial switch is designed and characterized for the purpose of crash sensing for ammunition systems in which high-speed response is required for triggering the detonator. In order to keep the same sensitivity in different direction, the structure of an annular proof-mass suspended by four serpentine flexures is designed. The switch can be integrated with electronics, fast-acting,and lack of a requirement for continuous power, and can be used in a wide area. The motion of the inertial switch is analyzed by dynamic simulation under the 700g threshold acceleration in y direction, the simulation results show that the response time is 0.142ms and the contact time of the switch is about 5 , it illustrates that the response time is short enough and the impact time satisfy the ask. The von-mises stress of the structure is calculate, the maximum stress occurs in the serpentine flexures, the value is 60.61 MPa, much less than the yield strength of the silicon, the switch can be used time after time.


2013 ◽  
Vol 739 ◽  
pp. 431-436
Author(s):  
Ho Kyung Kim

In order to evaluate the fatigue endurance for an ultra lightweight inline skate frame, FEM analyses was performed. The tensile properties and an S-N curve were determined through tensile and fatigue tests on a modified Al-7075+Sc alloy. The yield and ultimate tensile strengths were 553.3 MPa and 705.5 MPa, respectively. The fatigue endurance limit of this alloy was 201.2 MPa. To evaluate the fatigue endurance of the inline skate frame, the S-N data were compared with the stress analysis results through FEM analyses of the frame. The maximum von Mises stress of the frame was determined to be 106 MPa through FEM analysis of the frame, assuming that the skater weight is 75 kg. Conclusively, on the basis of the fatigue limit, the inline skate frame has a safety factor of approximately 2.0.


2018 ◽  
Vol 54 (5A) ◽  
pp. 174
Author(s):  
Pham Thi Hoa

Simulations of chip formulation mechanism and phenomenon ccurred in cutting processes can help to reduce time and cost comparing with experiment. Finite element method (FEM) is an effective and accurate technique, which can be used for simulation of cutting process. In this paper, chip formulation process in high-speed milling of A6061 aluminium alloy is investigated using FEM based on the Johnson-Cook (J-C) and Bao-Wierzbicki (B-W) fracture models. The Von-Mises stress distribution and equivalent plastic strain (PEEQ) during cutting are then investigated. Finally, the evolution of cutting forces in cutting was examined. The presented Finite element model in this study proved to be useful in determination of cutting parameters, especially in high-speed machining. 


2011 ◽  
Vol 314-316 ◽  
pp. 1713-1716
Author(s):  
You Ming Jiang ◽  
Yi Huang Zhang ◽  
Yun Feng He ◽  
Hui Yu Xiang ◽  
Jun Ci Cao

Considering the impact and the vibration that add to its driving system when high-speed MU running in the complex conditions, the rotor mechanical strength problems of a traction motor in MU power transmission system are studied, in this paper. The motor operating parameters when MU operating under different states, such as the starting process, the increasing voltage constant power process, and the constant voltage constant power process, are taken as the constraint boundary conditions in different situations. Considering the asymmetry of axial constraint, the distributions of both the Von Mises stress and the contact stress in rotor under different working states are analyzed, and the strength situation of rotor is evaluated. Then, the fatigue strength of rotor in a long duration rated operating is studied, and the fatigue weak position in rotor is found. The obtained results could provide a theoretical basis for the safety operation of traction motor in high-speed MU.


2017 ◽  
Vol 69 (3) ◽  
pp. 355-362
Author(s):  
Nor Amirah binti Mohd Amran ◽  
Mohd Sayuti bin Ab Karim ◽  
Rusdi bin Abd Rashid ◽  
Waleed Alghani ◽  
Nur Aqilah binti Derahman

Purpose This study aims to present a direct repurposing activity of consumed high-speed steel (HSS) hacksaw blade into fine-looking handmade knives to increase the awareness about sustainability by evaluating the relationship between the quality of material alloys and heat treatment as well as cultural aspects such as the treatment on the HSS hacksaw blade that will affect the material hardness. Design/methodology/approach The quality of HSS hacksaw blade samples was analyzed by using scanning electron microscope/energy dispersive X-Ray spectroscopy (SEM/EDX) through the identification of material element’s properties. Besides, finite element structural analysis was performed by using SolidWorks Simulation to evaluate the material performance by determining the Von Mises stress to find the factor of safety of the knife designs. Then, the effect of tribology implementation toward mechanical properties of the handmade knives was determined by using a Rockwell C hardness test. Findings It is found that the material composition of carbon plays a vital role in increasing and improving the hardness and wear resistance of the HSS hacksaw blade. The Von Mises stress obtained is lower than the yield strength of 3,250 MPa by 71.44 per cent with the safety factor of 3.58,which means the design will not be subjected to failure. The mechanical properties of the HSS hacksaw blade such as hardness were determined averagely by 5 per cent of hardness increase. Originality/value It has been validated that the tribological effect toward the material characteristic leads to hardness changes which contributed to the enhancement of tool life of the HSS hacksaw blade, thus producing better quality knives.


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