217 Numerical Analysis of Flow around Vehicle Model : Study of Numerical Accuracy of Yawing Moment

Computation of the distance between point and triangle in 3D is a common task in numerical analysis. The input values of the algorithm are coordinates of three points of the triangle and one point from which the distance is determined. An existing algorithm is extended to compute the gradient and the Hessian of that distance with respect to coordinates of involved points. Derivation of exact expressions for gradient and Hessian is presented, and numerical accuracy is evaluated for various cases. The algorithm has O(1) time and space complexity. The included open-source code may be used in applications where derivatives of point-triangle distance are required.

Download Full-text

Spatial Numerical Analysis Method of Coupled Vibration between Whole Vehicle Model and Curved Bridge Caused by Bridge Deck Roughness

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.446-449.1270 ◽

2012 ◽

Vol 446-449 ◽

pp. 1270-1276 ◽

Cited By ~ 1

Author(s):

Ying Shi ◽

Shan Ting Fang ◽

Qing Yong Tian ◽

Wei Chen

Keyword(s):

Numerical Analysis ◽

Degrees Of Freedom ◽

Bridge Deck ◽

Torsional Angle ◽

Analysis Method ◽

Coupled Vibration ◽

Vehicle Model ◽

Numerical Analysis Method ◽

Finite Element Software ◽

The Impact

In order to analyze the response and influencing factors from vehicle-bridge coupled vibration between curved continuous rigid frame bridge and whole vehicle model of 7 degrees of freedom, a spatial numerical analysis method of vehicle-bridge coupled vibration caused by bridge deck roughness was proposed. According to power spectrum density advised by GB/T 7031-2005, bridge deck roughness was simulated by the application of Fourier reverse transform. Because of delay of front and rear axles and correlation between left and right wheels, the roughness sequence of each wheel was obtained by the frequency response function solved by means of random vibration theory. The samples were taken as the input disturbances, rules of vehicle-bridge coupled vibration response under different grades of bridge deck were obtained using the finite element software ANSYS. Analysis results indicate that the value of dynamic coefficients of displacement and torsional angle increase sharply along with the grade increase of bridge deck roughness, and accurate simulation of bridge deck roughness is crucial for analyzing and evaluating the impact of vehicles on the bridge.

Download Full-text

Numerical analysis of synthetic granulate deposition in a physical model study

International Journal of Sediment Research ◽

10.1016/s1001-6279(14)60026-3 ◽

2014 ◽

Vol 29 (1) ◽

pp. 110-117 ◽

Cited By ~ 9

Author(s):

Gabriele HARB ◽

Stefan HAUN ◽

Josef SCHNEIDER ◽

Nils Reidar B. OLSEN

Keyword(s):

Numerical Analysis ◽

Physical Model ◽

Model Study

Download Full-text

Didactic application of numerical analysis in nonlinear dynamics: Lorenz model study

Optica Pura y Aplicada ◽

10.7149/opa.50.3.49009 ◽

2017 ◽

Vol 50 (3) ◽

pp. 197-219

Author(s):

F. V. García-Ferrer ◽

E. Roldán ◽

F. Silva ◽

G. J. de Valcárcel

Keyword(s):

Nonlinear Dynamics ◽

Numerical Analysis ◽

Lorenz Model ◽

Model Study

Download Full-text

Salsa: An Automatic Tool to Improve the Numerical Accuracy of Programs

10.29007/j2fd ◽

2018 ◽

Author(s):

Nasrine Damouche ◽

Matthieu Martel

Keyword(s):

Numerical Analysis ◽

Embedded Systems ◽

Software Architecture ◽

Static Analysis ◽

Abstract Interpretation ◽

Experimental Results ◽

Floating Point ◽

Numerical Accuracy ◽

Automatic Tool ◽

Concise Description

This article describes Salsa, an automatic tool to improve the accuracy of the floating- point computations done in numerical codes. Based on static analysis methods by abstract interpretation, our tool takes as input an original program, applies to it a set of transformations and then generates an optimized program which is more accurate than the initial one. The original and the transformed programs are written in the same imperative language. This article is a concise description of former work on the techniques implemented in Salsa, extended with a presentation of the main software architecture, the inputs and outputs of the tool as well as experimental results obtained by applying our tool on a set of sample programs coming from embedded systems and numerical analysis.

Download Full-text