A Forced Response Method for Annular Combustors Excited by Traveling Acoustic Pressure Waves

2008 ◽  
Author(s):  
Sanghum Baik ◽  
Mehmet Dede
Keyword(s):  
Finite Element ◽  
Pressure Wave ◽  
Acoustic Pressure ◽  
Response Prediction ◽  
Element Model ◽  
Forced Response ◽  
Response Analysis ◽  
Element Analysis ◽  
Variable Theory ◽  
Response Method

Recent progress in the development of an industry level tool for computing forced response of annular combustors is presented. Hereby, in addressing productivity issues caused by huge finite element model of full-wheel combustor, the theoretical framework of cyclic symmetry is introduced. The complex-variable theory, which originated for capturing natural frequency and mode shape characteristics of rotationally periodic structure, was extended for real-number-based finite element analysis (FEA) to solve forced response problem; specifically, a systematic method was developed to create cyclic domain replica of traveling pressure wave loading on full-wheel combustor. In this paper, theoretical descriptions of the physics-based, practical forced response analysis technique will be provided, and its implementation into building the tool of industrial level will be discussed. The technology developed herein will be verified using a simple cylindrical structure that is excited by acoustic pressure wave that travels in circumferential direction with a certain number of nodal diameter. In the end, a practical application to forced response prediction of a combustor component will be presented.

The Finite Element Analysis and Optimization for the Grinder Based on the Joint Surface

2013 ◽  
Vol 281 ◽  
pp. 165-169 ◽  
Author(s):  
Xiang Lei Zhang ◽  
Bin Yao ◽  
Wen Chang Zhao ◽  
Ou Yang Kun ◽  
Bo Shi Yao
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Element Model ◽  
Joint Surface ◽  
Weak Links ◽  
Response Analysis ◽  
Element Analysis ◽  
Static And Dynamic Analysis ◽  
Harmonic Response Analysis ◽  
Grinding Machine

Establish the finite element model for high precision grinding machine which takes joint surface into consideration and then carrys out the static and dynamic analysis of the grinder. After the static analysis, modal analysis and harmonic response analysis, the displacement deformation, stress, natural frequency and vibration mode could be found, which also helps find the weak links out. The improvement scheme which aims to increase the stiffness and precision of the whole machine has proposed to efficiently optimize the grinder. And the first natural frequency of the optimized grinder has increased by 68.19%.

Analysis of Crankshaft Fatigue Strength Based on Integrated Finite Element Model

2010 ◽  
Vol 44-47 ◽  
pp. 1558-1562 ◽  
Author(s):  
Xiao Ping Chen ◽  
Ru Fu Hu ◽  
Shu Hua Zheng
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Fatigue Limit ◽  
Limit Load ◽  
Element Model ◽  
Response Analysis ◽  
Analysis Model ◽  
Element Analysis ◽  
Complex Mechanical Systems ◽  
Multi Body

Aiming at the complex mechanical systems for the prediction of the fatigue limit load requirements, this paper examines the relationship among finite element analysis model and the performance models. And a finite element modeling method for fatigue analysis is proposed. The finite element model can support static, modal, fatigue, and multi-body dynamic response analysis in parallel and collaboration. This method helps improve the fatigue limit load analysis.

Finite Element Analysis of Air Cooler Using Equivalent Static Method and Response Spectrum Method Respectively

2011 ◽  
Vol 250-253 ◽  
pp. 2955-2958
Author(s):  
Shao Qing Hu ◽  
Bai Tao Sun
Keyword(s):  
Finite Element ◽  
Static Load ◽  
Response Spectrum ◽  
Element Model ◽  
Response Spectrum Method ◽  
Element Analysis ◽  
Spectrum Method ◽  
Equivalent Static Load ◽  
Air Cooler ◽  
Response Method

Based on the characteristic of cooler frame, the finite element model of air cooler frame is established using ANSYS software. Equivalent static load method and response spectrum method were used for the seismic performance analysis of cooler frame. The equivalent static load is applied at the center of gravity of various masses using MPC184 rigid beam for transferring the load. The deformation and stress of cooler using equivalent static load method are larger than that of cooler using spectrum response method. For this reason, it can be said that the equivalent static load method is more conservative. At last the deformations and stresses of cooler frame using two methods are checked by ASME AG-1 specification. The results showed that the deformation and stress of cooler frame meet the requirements.

Harmonic Convergence Estimation Through Strain Energy Superconvergence

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Alexander A. Kaszynski ◽  
Joseph A. Beck ◽  
Jeffrey M. Brown
Keyword(s):  
Finite Element ◽  
Strain Energy ◽  
Response Prediction ◽  
Element Model ◽  
Accurate Estimate ◽  
Element Analysis ◽  
Modeling Process ◽  
Harmonic Convergence ◽  
Convergence Study ◽  
Polyharmonic Splines

Grid convergence in finite element analysis (FEA), despite a wide variety of tools available to date, remains an elusive and challenging task. Due to the complex and time-consuming process of remeshing and solving the finite element model (FEM), convergence studies can be a part of the most arduous portion of the modeling process and can even be impossible with FEMs unassociated with CAD. Existing a posteriori methods, such as relative error in the energy norm, provide a near arbitrary indication of the model convergence for eigenfrequencies. This paper proposes a new approach to evaluate the harmonic convergence of an existing model without conducting a convergence study. Strain energy superconvergence (SES) takes advantage of superconvergence points within a FEM and accurately recovers the strain energy within the model using polyharmonic splines, thus providing a more accurate estimate of the system's eigenfrequencies without modification of the FEM. Accurate eigenfrequencies are critical for designing for airfoil resonance avoidance and mistuned rotor response prediction. Traditional error estimation strategies fail to capture harmonic convergence as effectively as SES, potentially leading to a less accurate airfoil resonance and rotor mistuning prediction.

Harmonic Convergence Estimation Through Strain Energy Superconvergence

2015 ◽  
Author(s):  
Alexander A. Kaszynski ◽  
Joseph A. Beck ◽  
Jeffrey M. Brown
Keyword(s):  
Finite Element ◽  
Strain Energy ◽  
Response Prediction ◽  
Element Model ◽  
Accurate Estimate ◽  
Element Analysis ◽  
Modeling Process ◽  
Harmonic Convergence ◽  
Convergence Study ◽  
Polyharmonic Splines

Grid convergence in finite element analysis, despite a wide variety of tools available to date, remains an elusive and challenging task. Due to the complex and time consuming process of remeshing and solving the finite element model (FEM), convergence studies can be part of the most arduous portion of the modeling process and can even be impossible with FEMs unassociated with CAD. Existing a posteriori methods, such as relative error in the energy norm, provide a near arbitrary indication of the model convergence for eigenfrequencies. This paper proposes a new approach to evaluate the harmonic convergence of an existing model without conducting a convergence study. Strain energy superconvergence takes advantage of superconvergence points within a FEM and accurately recovers the strain energy within the model using polyharmonic splines, thus providing a more accurate estimate of the system’s eigenfrequencies without modification of the FEM. Accurate eigenfrequencies are critical for designing for airfoil resonance avoidance and mistuned rotor response prediction. Traditional error estimation strategies fail to capture harmonic convergence as effectively as SES, potentially leading to a less accurate airfoil resonance and rotor mistuning prediction.

The Forced Response Analysis of Heavy Duty Vehicle’s Cab

2014 ◽  
Vol 599-601 ◽  
pp. 503-506
Author(s):  
Jun Liang Liu ◽  
Yu Hong Long ◽  
Wen Shang Li ◽  
Jie Cai
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Theoretical Basis ◽  
Element Model ◽  
Forced Response ◽  
Response Analysis ◽  
Heavy Duty ◽  
Inherent Frequency ◽  
The Impact ◽  
Response Region

An automobile will sustain various incentives from the outside and inside in the process of being driven, in which the impact of the wheel and the vibration of engine mainly dominates. This paper gets the inherent frequency through modal analysis on finite element model in a heavy vehicle’s driving cab. And then it conducts the forced response analysis on finite element model by modeling a condition where the vibration of driving cab is caused by outside incentive. Through analyzing, it finds the main response region generated in driving cab when affected by outside incentive. At the same time, it can provide certain theoretical basis for controlling the noise of driving cab in the future.

Finite Element Analysis for Vibration Characteristic on Gear Rotors

2013 ◽  
Vol 273 ◽  
pp. 193-197
Author(s):  
Hong Yu Qi ◽  
Lei Liu
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Helix Angle ◽  
Forced Response ◽  
Rotor System ◽  
Ansys Software ◽  
Element Analysis ◽  
Rotor Systems ◽  
Rotational Motions ◽  
Marine Applications

Gear rotor systems are widely used in many automotive, aerospace and marine applications. Dynamic analysis of gear rotor systems is essential in describing noise and durability characteristics. Using ANSYS software, a finite-element model for a gear rotor system on flexible bearing has been developed, with MARTIX element, beam element and mass element simulating mesh-couple relation and support bearing, shaft and gear individually. The dynamic coupling among the axial, transverse, tensional and rotational motions of gears are considered in the model. The harmonic analysis and forced response of the system were analyzed. The effect of bearing compliances, shaft compliances and helix angle on system dynamics were investigated. The feasibility of the method was verified, the model and result can be used for dynamic design of gear rotor system.

Dynamic Analysis Based on ANSYS of Turning and Grinding Compound Machine Spindle Box

2012 ◽  
Vol 433-440 ◽  
pp. 524-529
Author(s):  
Zhan Hui Shu ◽  
Qiu Shi Han
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Machine Tools ◽  
High Speed ◽  
High Efficiency ◽  
Three Dimensional ◽  
Element Model ◽  
Response Analysis ◽  
Element Analysis ◽  
Analysis And Design

With constant development of machine tools toward the direction of high speed, high precision, high efficiency and high compound rapidly. The performance of high-speed machine tools is affected by the dynamic characteristic of machine tools in the very great degree. More and more attention is played to them and higher and higher demands are proposed. Finite element method is a kind of fast and efficient auxiliary tools in modern engineering analysis and design. Three-dimensional finite element model of spindle box is established in this paper based on large finite element analysis software ANSYS. Through modal analysis, the first five order natural frequency, vibration mode and various order vibrating modal characteristics are obtained. These results are verified by using the method of experimental modal. Harmonic response analysis is carried after doing modal analysis on spindle box. Response and stress under different frequency are obtained. Continuous dynamic characteristics are forecasted.

КОНСТРУКТИВНО-ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ХВОСТО-ВИХ БАЛОК СІТЧАСТОГО ТИПУ З ПОЛІМЕРНИХ КОМПО-ЗИЦІЙНИХ МАТЕРІАЛІВ ВЕРТОЛЬОТІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

2020 ◽  
pp. 15-30
Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Layer Structure ◽  
Metal Structure ◽  
Element Model ◽  
Stress Strain ◽  
Element Analysis ◽  
Mesh Structure ◽  
Stress Strain State ◽  
Mesh Structures

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.

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