Influence of aspect ratio on the linear and non-linear steady state forced vibration response of cylindrical open shells

In this paper, a generalized nonlinear time-varying multibody dynamic model of dual clutch transmissions (DCT) is presented. The model consists of clutches, shafts, gears and synchronizers, and can be used to model any DCT architecture. A nonlinear clutch model is used to determine the transmitted power to the transmission at any speed and clutch temperature. The clutch can be a single- or multi-plate clutch and can operate in a wet or dry-clutch configuration. A combined kinematic and powerflow simulation enables calculation of gear, shaft, bearing and clutch quasi-static loads as well as gear mesh frequencies following a duty cycle as the input. For the corresponding Linear-Time-Invariant (LTI) system model, natural frequencies and mode shapes are obtained by solving the eigenvalue problem. The modal summation technique is used to determine the steady state forced vibration response of the system. For the corresponding NTV system, Newmark's time-step marching based integration is used to determine both the steady state and transient forced vibration response of the system. The DCT model is exercised using a common transmission architecture operating at several different operating conditions. The resulting impact of changing operational conditions on gear and bearing loads as well as dynamic transmission error spectra are demonstrated.

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An Adaptive Perturbation Scheme for the Analysis of Mistuned Bladed Disks

Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; Education; IGTI Scholar Award ◽

10.1115/95-gt-455 ◽

1995 ◽

Author(s):

Chung-Chih Lin ◽

Marc P. Mignolet

Keyword(s):

Steady State ◽

Forced Vibration ◽

Perturbation Technique ◽

Computational Effort ◽

Vibration Response ◽

Perturbation Scheme ◽

Bladed Disks ◽

Steady State Analysis ◽

At Will

In this paper, a novel perturbation technique is introduced for the determination of the forced vibration response of mistimed bladed disks. The proposed technique is adaptive in the sense that the level of approximation can be varied at will to accommodate any specificities of the tuned system and/or of the existing mistuning. This versatility of the proposed approach not only guarantees the reliability of the computed response but also leads to an excellent compromise between accuracy and computational effort. Numerical results are presented that demonstrate both the reliability of the computed response and the computational saving obtained by relying on the suggested perturbation technique as opposed to a straightforward steady state analysis.

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On the Large Amplitude Forced Vibration Analysis of Composite Sectorial Plates

Journal of Composites Science ◽

10.3390/jcs5030083 ◽

2021 ◽

Vol 5 (3) ◽

pp. 83

Author(s):

Ahmad Saood ◽

Zain A. Khan ◽

Mohd T. Parvez ◽

Arshad H. Khan

Keyword(s):

Steady State ◽

Forced Vibration ◽

Large Amplitude ◽

Laminated Composite ◽

Vibration Response ◽

Arc Length ◽

Annular Sector ◽

Sector Plate ◽

Annular Sector Plate ◽

State Stress

The nonlinear steady state large amplitude forced vibration response of a laminated composite annular sector plate is presented. The nonlinear governing equation of motion of the laminated composite annular sector plate has been obtained using kinematics of first-order shear deformation theory (FSDT) and employing Hamilton’s principle. The governing equations of motion have been solved in a time domain using a modified shooting method and arc-length/pseudo-arc length continuation technique. The influence of the boundary condition, sector angle, and annularity ratio on the linear as well as nonlinear steady state forced vibration response has been investigated. The strain/stress variation across the thickness of the annular sector plate is presented to explain the reason for a decrease/increase in hardening nonlinear behaviour. The periodic variation of the non-linear steady state stress has also been obtained to throw light into the factors influencing the unequal stress half cycles and multiple cyclic stress reversals, which is detrimental to the fatigue design of laminated composite annular sectorial plates. The frequency spectra of the steady state stress reveals large even and odd higher harmonic contributions for different cases due to changes in the restoring force dynamics. The modal interaction/exchange during a cycle is demonstrated using a deformed configuration of the laminated annular sector plate.

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Effect of boundary conditions on the non-linear forced vibration response of isotropic plates

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/377/1/012089 ◽

2018 ◽

Vol 377 ◽

pp. 012089

Author(s):

M Shariq Beg ◽

Arshad Hussain Khan ◽

M Yaqoob Yasin

Keyword(s):

Boundary Conditions ◽

Forced Vibration ◽

Vibration Response ◽

Isotropic Plates ◽

Non Linear

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An Adaptive Perturbation Scheme for the Analysis of Mistuned Bladed Disks

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2815540 ◽

1997 ◽

Vol 119 (1) ◽

pp. 153-160 ◽

Cited By ~ 25

Author(s):

C.-C. Lin ◽

M. P. Mignolet

Keyword(s):

Steady State ◽

Forced Vibration ◽

Perturbation Technique ◽

Computational Effort ◽

Vibration Response ◽

Perturbation Scheme ◽

Bladed Disks ◽

Steady State Analysis ◽

At Will

In this paper, a novel perturbation technique is introduced for the determination of the forced vibration response of mistuned bladed disks. The proposed technique is adaptive in the sense that the level of approximation can be varied at will to accommodate any specificities of the tuned system and/or of the existing mistuning. This versatility of the proposed approach not only guarantees the reliability of the computed response but also leads to an excellent compromise between accuracy and computational effort. Numerical results are presented that demonstrate both the reliability of the computed response and the computational saving obtained by relying on the suggested perturbation technique as opposed to a straightforward steady-state analysis.

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A Simple Analytical Expression of Non-Linear Boundary Value Problem for Steady State Thermal Criticality in Viscous Reactive Flows Through Channels With A Sliding Wall

International Journal of Scientific Research ◽

10.15373/22778179/march2014/65 ◽

2012 ◽

Vol 3 (3) ◽

pp. 194-200

Author(s):

V. Ananthaswamy V. Ananthaswamy ◽

◽

S. Mythili S. Mythili

Keyword(s):

Steady State ◽

Boundary Value Problem ◽

Boundary Value ◽

Linear Boundary ◽

Reactive Flows ◽

Simple Analytical Expression ◽

Analytical Expression ◽

Non Linear ◽

Thermal Criticality ◽

Linear Boundary Value Problem

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Analysis of Single Buffer Random Polling System With State-Dependent Input Process and Server/Station Breakdowns

International Journal of Operations Research and Information Systems ◽

10.4018/ijoris.2018010102 ◽

2018 ◽

Vol 9 (1) ◽

pp. 22-50 ◽

Cited By ~ 2

Author(s):

Thomas Y.S. Lee

Keyword(s):

Steady State ◽

Linear Model ◽

Repair Process ◽

Polling System ◽

Steady State Analysis ◽

Relaxation System ◽

Polling Model ◽

State Dependent ◽

Non Linear ◽

State Analysis

Models and analytical techniques are developed to evaluate the performance of two variations of single buffers (conventional and buffer relaxation system) multiple queues system. In the conventional system, each queue can have at most one customer at any time and newly arriving customers find the buffer full are lost. In the buffer relaxation system, the queue being served may have two customers, while each of the other queues may have at most one customer. Thomas Y.S. Lee developed a state-dependent non-linear model of uncertainty for analyzing a random polling system with server breakdown/repair, multi-phase service, correlated input processes, and single buffers. The state-dependent non-linear model of uncertainty introduced in this paper allows us to incorporate correlated arrival processes where the customer arrival rate depends on the location of the server and/or the server's mode of operation into the polling model. The author allows the possibility that the server is unreliable. Specifically, when the server visits a queue, Lee assumes that the system is subject to two types of failures: queue-dependent, and general. General failures are observed upon server arrival at a queue. But there are two possibilities that a queue-dependent breakdown (if occurs) can be observed; (i) is observed immediately when it occurs and (ii) is observed only at the end of the current service. In both cases, a repair process is initiated immediately after the queue-dependent breakdown is observed. The author's model allows the possibility of the server breakdowns/repair process to be non-stationary in the number of breakdowns/repairs to reflect that breakdowns/repairs or customer processing may be progressively easier or harder, or that they follow a more general learning curve. Thomas Y.S. Lee will show that his model encompasses a variety of examples. He was able to perform both transient and steady state analysis. The steady state analysis allows us to compute several performance measures including the average customer waiting time, loss probability, throughput and mean cycle time.

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