Matrix Analysis Method for Direct and Multiple Contact Multibody Systems

1990 ◽  
Vol 112 (2) ◽  
pp. 145-152 ◽  
Author(s):  
P. N. Sheth ◽  
T. M. Hodges ◽  
J. J. Uicker

A generalized modeling procedure for curves and surfaces in direct contact relative motions is developed, such that these joints can be consistently included in the well-developed and established (4 × 4) matrix method for kinematic, static, and dynamic analyses of geometrically constrained lower paired multibody mechanical systems. The modeling procedure allows both the analytical and the discretized Geometric Modeling approaches. As one application of these analytical techniques, a numerical procedure for mobility analysis of multiple contact joints is presented and illustrated. Other applications of this development are enumerated.

Author(s):  
Apiwat Reungwetwattana ◽  
Shigeki Toyama

Abstract This paper presents an efficient extension of Rosenthal’s order-n algorithm for multibody systems containing closed loops. Closed topological loops are handled by cut joint technique. Violation of the kinematic constraint equations of cut joints is corrected by Baumgarte’s constraint violation stabilization method. A reliable approach for selecting the parameters used in the constraint stabilization method is proposed. Dynamic analysis of a slider crank mechanism is carried out to demonstrate efficiency of the proposed method.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Inayat Ullah ◽  
M. T. Rahim ◽  
Hamid Khan ◽  
Mubashir Qayyum

The aim of the present work is to analyze the magnetohydrodynamic (MHD) squeezing flow through porous medium using homotopy analysis method (HAM). Fourth-order boundary value problem is modeled through stream functionψ(r,z)and transformationψ(r,z)=r2f(z). Absolute residuals are used to check the efficiency and consistency of HAM. Other analytical techniques are compared with the present work. It is shown that results of good agreement can be obtained by choosing a suitable value of convergence control parameterhin the valid regionRh. The influence of different parameters on the flow is argued theoretically as well as graphically.


1988 ◽  
Vol 1 (21) ◽  
pp. 23
Author(s):  
Toru Sawaragi ◽  
Ichiro Deguchi ◽  
San-Kil Park

A wave overtopping rate from a sea dike of various toe depths is formulated based on a weir model in an unidirectional flow. To evaluated the wave overtopping rate from a seadike on an artificial reef by the weir model, a numerical procedure for predicting wave transformations including the effect of forced wave breaking on the reef is constructed. After confirming the applicability of the model through experiments with regular and irregular waves, the effect of artificial reef on wave overtopping is discussed. So-called individual wave analysis method is shown to he applicable to the wave overtopping caused by irregular waves.


1967 ◽  
Vol 4 (04) ◽  
pp. 331-354
Author(s):  
R. L. Harrington ◽  
W. S. Vorus

A description and evaluation of the dynamic analysis method of determining the shock resistance of shipboard equipment is given. Development of equipment mathematical models is treated in detail, and the computational procedures used in conducting dynamic analyses are illustrated. Considerations in the preparation of dynamic-analysis reports are discussed. Discussers R. S. Adelizzi G. W. Bishop V. T. Boatwright K. J. Calvin C. Dotson Capt. H. C. Field, Jr., USND. W. Ginter O. Gould D. M. Gray K. Gyswyt R. T. Hawley RADM L. V. Honsinger, USN(Ret.) C. Lee J. C. Lester C. Li W. A. Littlejohn N. J. Monroe A. Morrone B. Novak E. W. Palmer C. G. Puffenburger L. L. Salter H.M. Schauer J. R. Sullivan J. D. Swannack C. Y. Tiao H. H. Ward W. P. Welch J. B. Woodward, III


2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Mehmet Şenol ◽  
Olaniyi S. Iyiola ◽  
Hamed Daei Kasmaei ◽  
Lanre Akinyemi

Abstract In this paper, we present analytical-approximate solution to the time-fractional nonlinear coupled Jaulent–Miodek system of equations which comes with an energy-dependent Schrödinger potential by means of a residual power series method (RSPM) and a q-homotopy analysis method (q-HAM). These methods produce convergent series solutions with easily computable components. Using a specific example, a comparison analysis is done between these methods and the exact solution. The numerical results show that present methods are competitive, powerful, reliable, and easy to implement for strongly nonlinear fractional differential equations.


Author(s):  
Sergey Timushev ◽  
Alexandr Gamarnik ◽  
Anton Tsipenko

The noise of domestic machines including lawnmowers be comes an urgent issue. As the technology matures, designers need better tools to predict performance and efficiency of these machines across a wide range of operating conditions and find optimal ways to reduce noise. Computational fluid dynamics is an increasingly powerful tool which enables designer to better understand all features of unsteady flow in these machines and to find optimal designs providing higher energetic characteristics, better cutting quality and lower pressure pulsation, vibration and noise. Cutting quality linked with evacuation of grass is a key lawnmower characteristic. Due to this fact application of two-phase (air-grass) lawnmower flow model is inevitable in a prediction procedure. The modeling procedure comprises determination of lawnmower average aerodynamic characteristics and CFD-CAA analysis by acoustic-vortex method to predict sound power data. This method is based on splitting the equations of compressible fluid dynamics into two modes — vortex and acoustic Computational approach applied for the vortex mode flow is a “moving body”-technique: The problem is solved in the absolute frame of coordinates and computational grid changes during the blade passing. Computations can be made in 4 stages: 1) Computation of the incompressible medium with getting average values of energetic parameters; 2) Computation of the incompressible medium for definition the source function of inhomogeneous acoustic-vortex wave equation; 3) Solution of the acoustic-vortex wave equation; 4) Computation of 2-phase flow. In the 3rd stage the pressure pulsation field can be represented like a sum of acoustic and vortex oscillation. Wave equation is solved relatively to pressure oscillation using an explicit numerical procedure. Zero pulsatory pressure is an initial condition for solution of the wave equation. The local complex specific acoustic impedance is used to define boundary conditions for the acoustical part of the pressure field. Thus the numerical procedure gives pressure pulsations field and sound power data on blade passing frequencies (BPF). For the 4th stage computations effective grass particle parameters are determined with accounting the stubble effect on flow parameters and particularities of grass particle interaction with rigid surfaces. Results of a lawnmower air-grass flow (grass particle trajectories and concentration) and corresponding BPF sound power data prediction are presented as an example of modeling procedure application.


2010 ◽  
Vol 18 (04) ◽  
pp. 711-725 ◽  
Author(s):  
JIAN-JUN SHU ◽  
YAJING LI

A hypercomplex representation of DNA is proposed to facilitate comparing DNA sequences with fuzzy composition. With the hypercomplex number representation, the conventional sequence analysis method, such as, dot matrix analysis, dynamic programming, and cross-correlation method have been extended and improved to align DNA sequences with fuzzy composition. The hypercomplex dot matrix analysis can provide more control over the degree of alignment desired. A new scoring system has been proposed to accommodate the hypercomplex number representation of DNA and integrated with dynamic programming alignment method. By using hypercomplex cross-correlation, the match and mismatch alignment information between two aligned DNA sequences are separately stored in the resultant real part and imaginary parts respectively. The mismatch alignment information is very useful to refine consensus sequence based motif scanning.


Sign in / Sign up

Export Citation Format

Share Document