Effect of the Elastic Restraint by Adjacent Plate Component on the Local Buckling of Orthotropic Box-Shape Flexural Members

2005 ◽  
Vol 297-300 ◽  
pp. 1253-1258
Author(s):  
Jae Ho Jung ◽  
Soon Jong Yoon ◽  
Sung Kun You ◽  
Seok Goo Youn
Keyword(s):  
Analytical Procedure ◽  
Local Buckling ◽  
Closed Form Solution ◽  
Form Solution ◽  
Buckling Analysis ◽  
Factors Affecting ◽  
Flexural Members ◽  
Theoretical Predictions ◽  
Flexural Member ◽  
Elastically Restrained

The local buckling analysis of thin walled member is generally conducted by modeling each plate component as an isolated plate with elastically restrained boundaries. When this analytical model is used for the orthotropic flexural members, it is necessary to obtain the degree of elastic restraint provided by adjacent plate. In this study, the equation to find the coefficient of elastic restraint by adjacent plate components of an orthotropic box-shape flexural member was derived by employing the energy approach, and the factors affecting the elastic restraint were briefly discussed. Using the suggested equation, the coefficient of elastic restraint was calculated, and the local buckling analysis was conducted according to the stepwise analytical procedure published by the authors. The theoretical predictions were in good agreement with results obtained by the closed-form solution. The local buckling strength of an orthotropic box-shape flexural member can be easily obtained through stepwise analytical procedure with the proposed equation that accounts for the effect of elastic restraint imposed by adjacent plate components.

Elastic Buckling Strength of Restrained Orthotropic Web Plates

2004 ◽  
Vol 261-263 ◽  
pp. 615-620
Author(s):  
Jae Ho Jung ◽  
Soon Jong Yoon ◽  
S.K. You
Keyword(s):  
Local Buckling ◽  
Solution Technique ◽  
Power Series Solution ◽  
Flexural Members ◽  
Buckling Strength ◽  
Longitudinal Edge ◽  
Flexural Member ◽  
Degree Of Restraint ◽  
Elastically Restrained ◽  
Web Plates

In this paper, the buckling behavior of elastically restrained orthotropic web plates is investigated. In general, the pultruded FRP structural member is composed of flat plate elements and each plate element is elastically restrained against rotation by adjacent plate components. For finding the local buckling strength of composite flexural member considering the elastic restraint at the juncture of plate components, the orthotropic web plate is modeled as an elastically restrained orthotropic plate under linearly distributed in-plane forces. For the derivation of buckling equation, the power series solution technique is employed. For the plate having different mechanical properties, the parametric studies are conducted by varying the degree of restraint along the longitudinal edge under compression. By using the results obtained, simplified form of equation is also developed so that the practicing engineers can evaluate the buckling stress of such a plate for the preliminary design of FRP flexural members.

Design and Analysis of Automotive Serpentine Belt Drive Systems for Steady State Performance

1997 ◽  
Vol 119 (2) ◽  
pp. 162-168 ◽  
Author(s):  
R. S. Beikmann ◽  
N. C. Perkins ◽  
A. G. Ulsoy
Keyword(s):  
Steady State ◽  
Closed Form ◽  
Closed Form Solution ◽  
Form Solution ◽  
Design Parameters ◽  
Belt Drive ◽  
Automotive Engine ◽  
Theoretical Predictions ◽  
Serpentine Belt ◽  
Drive Systems

Serpentine belt drive systems with spring-loaded tensioners are now widely used in automotive engine accessory drive design. The steady state tension in each belt span is a major factor affecting belt slip and vibration. These tensions are determined by the accessory loads, the accessory drive geometry, and the tensioner properties. This paper focuses on the design parameters that determine how effectively the tensioner maintains a constant tractive belt tension, despite belt stretch due to accessory loads and belt speed. A nonlinear model predicting the operating state of the belt/tensioner system is derived, and solved using (1) numerical, and (2) approximate, closed-form methods. Inspection of the closed-form solution reveals a single design parameter, referred to as the “tensioner constant,” that measures the effectiveness of the tensioner. Tension measurements on an experimental drive system confirm the theoretical predictions.

Seismic Response of Unanchored Fluid-Filled Tanks Using Finite Elements

1992 ◽  
Vol 114 (1) ◽  
pp. 74-79 ◽  
Author(s):  
Wei Yi ◽  
S. Natsiavas
Keyword(s):  
Finite Elements ◽  
Seismic Response ◽  
Analytical Procedure ◽  
Equations Of Motion ◽  
Closed Form Solution ◽  
Element Model ◽  
Form Solution ◽  
Structural Domain ◽  
Hydrodynamic Response ◽  
Strong Ground

A finite element model is presented for the seismic response of liquid-filled tanks. This type of analysis is complicated for unanchored tanks, because the bases of these tanks separate from their foundations during strong ground motion. This changes the dynamic behavior of these structures considerably and may result in severe loading. The analysis starts by geometrically discretizing the shell structure using cylindrical finite elements. Then, application of Hamilton’s principle in the structural domain yields the equations of motion for the coupled fluid/structure system. The foregoing analytical procedure employs the closed-form solution for the hydrodynamic response problem, resulting in a compact system of equations of motion. Primary attention is paid to the formulation of the nonlinear base uplift problem. Effects due to shell and ground flexibility are also included.

Free Vibration of Serpentine Belt Drive Systems

1996 ◽  
Vol 118 (3) ◽  
pp. 406-413 ◽  
Author(s):  
R. S. Beikmann ◽  
N. C. Perkins ◽  
A. G. Ulsoy
Keyword(s):  
Closed Form Solution ◽  
Form Solution ◽  
Drive System ◽  
Belt Drive ◽  
Free Response ◽  
Coupled Equations ◽  
Theoretical Predictions ◽  
Serpentine Belt ◽  
Drive Systems ◽  
Excessive Noise

The vibration of an automotive serpentine belt drive system greatly affects the perceived quality and the reliability of the system. Accessory drives with unfavorable vibration characteristics transmit excessive noise and vibration to other vehicle structures, to the vehicle occupants, and may also promote the fatigue and failure of system components. Moreover, these characteristics are a consequence of decisions made early on in the design and arrangement of the accessory drive system. The present paper focuses on fundamental modeling issues that are central to predicting accessory drive vibration. To this end, a prototypical drive is evaluated, which is composed of a driven pulley, a driving pulley, and a dynamic tensioner. The coupled equations of free response governing the discrete and continuous elements are presented herein. A closed-form solution method is used to evaluate the natural frequencies and modeshapes. Attention focuses on a key linear mechanism that couples tensioner arm rotation and transverse vibration of the adjacent belt spans. Modal tests on an experimental drive confirm the theoretical predictions.

Structural Performance of Buried Steel Pipelines Crossing Strike-Slip Faults

2014 ◽  
Author(s):  
Polynikis Vazouras ◽  
Panos Dakoulas ◽  
Spyros A. Karamanos
Keyword(s):  
Closed Form ◽  
Local Buckling ◽  
Closed Form Solution ◽  
Strike Slip ◽  
Form Solution ◽  
Strike Slip Fault ◽  
Performance Criteria ◽  
Cross Sectional ◽  
Soil System ◽  
Inelastic Material

The performance of pipelines subjected to permanent strike-slip fault movement is investigated by combining detailed numerical simulations and closed-form solutions. A closed-form solution for the force-displacement relationship of a buried pipeline subjected to tension is presented and used in the form of nonlinear springs at the two ends of the pipeline in a refined finite element model, allowing an efficient nonlinear analysis of the pipe-soil system at large strike-slip fault movements. The analysis accounts for large deformations, inelastic material behaviour of the pipeline and the surrounding soil, as well as contact and friction conditions on the soil-pipe interface. Appropriate performance criteria of the steel pipeline are adopted and monitored throughout the analysis. It is shown that the end conditions of the pipeline have a significant influence on pipeline performance. For a strike-slip fault normal to the pipeline axis, local buckling occurs at relatively small fault displacements. As the angle between the fault normal and the pipeline axis increases, local buckling can be avoided due to longitudinal stretching, but the pipeline may fail due to excessive axial tensile strains or cross sectional flattening.

scholarly journals Parameter inference and model comparison using theoretical predictions from noisy simulations

2019 ◽  
Vol 490 (4) ◽  
pp. 5749-5756 ◽  
Author(s):  
Niall Jeffrey ◽  
Filipe B Abdalla
Keyword(s):  
Model Comparison ◽  
Closed Form Solution ◽  
Power Spectra ◽  
Simulated Data ◽  
Analysis Data ◽  
Form Solution ◽  
Summary Statistic ◽  
Unknown Parameters ◽  
Light Curve Analysis ◽  
Theoretical Predictions

ABSTRACT When inferring unknown parameters or comparing different models, data must be compared to underlying theory. Even if a model has no closed-form solution to derive summary statistics, it is often still possible to simulate mock data in order to generate theoretical predictions. For realistic simulations of noisy data, this is identical to drawing realizations of the data from a likelihood distribution. Though the estimated summary statistic from simulated data vectors may be unbiased, the estimator has variance that should be accounted for. We show how to correct the likelihood in the presence of an estimated summary statistic by marginalizing over the true summary statistic in the framework of a Bayesian hierarchical model. For Gaussian likelihoods where the covariance must also be estimated from simulations, we present an alteration to the Sellentin–Heavens corrected likelihood. We show that excluding the proposed correction leads to an incorrect estimate of the Bayesian evidence with Joint Light-Curve Analysis data. The correction is highly relevant for cosmological inference that relies on simulated data for theory (e.g. weak lensing peak statistics and simulated power spectra) and can reduce the number of simulations required.

Sign in / Sign up

Export Citation Format

Share Document