Engineering AnalysisPub Date : 1988-12-01Epub Date: 2003-04-03DOI: 10.1016/0264-682X(88)90017-2
M.H Aliabadi, W.S Hall
{"title":"Nonisoparametric formulations for the three-dimensional boundary element method","authors":"M.H Aliabadi, W.S Hall","doi":"10.1016/0264-682X(88)90017-2","DOIUrl":"10.1016/0264-682X(88)90017-2","url":null,"abstract":"<div><p>The paper investigates the inaccuracies arising from discretization procedures in the three-dimensional Boundary Element Method for potential problems, particularly from the representation of the surface and unknown function by interpolating shape functions. Nonisoparametric formulations are considered; that is, sub-parametric in which the surface is not as well represented as the unknown function, and super-parametric in which the surface is better represented than the unknown function. These nonisoparametric formulations are based on 8-node and 9-node quadrilaterals which are also used to provide two different levels of isoparametric formulations.</p><p>Numerical results based on the various formulations are presented for some problems for which exact solutions are known. Firstly, Dirichlet problems of finding the surface charge for a unit sphere with given uniform and nonuniform potentials corresponding to first and second order harmonics; secondly, a Neuman problem of finding the velocity potential on a sphere placed in a uniform stream.</p><p>The results show that there is an advantage in accuracy and reduced calculation time for the super-parametric formulation compared to iso-parametric formulations. The sub-parametric formulation in which the unknown function is better represented than the surface is less accurate and offers no time reduction. It also presents special difficulties in defining the position of any extra unknown function node not corresponding to a surface node.</p></div>","PeriodicalId":100474,"journal":{"name":"Engineering Analysis","volume":"5 4","pages":"Pages 198-204"},"PeriodicalIF":0.0,"publicationDate":"1988-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0264-682X(88)90017-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74486673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Engineering AnalysisPub Date : 1988-12-01Epub Date: 2003-04-03DOI: 10.1016/0264-682X(88)90020-2
{"title":"International society for boundary elements (I.S.B.E.)","authors":"","doi":"10.1016/0264-682X(88)90020-2","DOIUrl":"https://doi.org/10.1016/0264-682X(88)90020-2","url":null,"abstract":"","PeriodicalId":100474,"journal":{"name":"Engineering Analysis","volume":"5 4","pages":"Page 215"},"PeriodicalIF":0.0,"publicationDate":"1988-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0264-682X(88)90020-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92143762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Engineering AnalysisPub Date : 1988-12-01Epub Date: 2003-04-03DOI: 10.1016/0264-682X(88)90015-9
Hiroyoshi Hirai
{"title":"Analysis of transient response of SH wave scattering in a half space by the boundary element method","authors":"Hiroyoshi Hirai","doi":"10.1016/0264-682X(88)90015-9","DOIUrl":"10.1016/0264-682X(88)90015-9","url":null,"abstract":"<div><p>The numerical implementation for analyzing time-dependent problems of scattering and diffraction of elastic waves by surface irregularities is presented. In order to develop the analysis of the two-dimensional elastodynamic problem of the SH wave field in a half space, the direct boundary element method is considered by means of the time domain formulation in combination with time-stepping integral schemes. Both spatial and time variations of surface amplitudes are computed for semi-circular and triangular canyons. Numerical solutions of transient-state response at larger times are compared with the known solutions of steady-state response and a good agreement is observed between these results.</p></div>","PeriodicalId":100474,"journal":{"name":"Engineering Analysis","volume":"5 4","pages":"Pages 189-194"},"PeriodicalIF":0.0,"publicationDate":"1988-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0264-682X(88)90015-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87818341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Engineering AnalysisPub Date : 1988-12-01Epub Date: 2003-04-03DOI: 10.1016/0264-682X(88)90019-6
Dorel Homentcovschi
{"title":"An analytic solution to the poisson equation in some plane domains","authors":"Dorel Homentcovschi","doi":"10.1016/0264-682X(88)90019-6","DOIUrl":"10.1016/0264-682X(88)90019-6","url":null,"abstract":"<div><p>The paper proposes a particular analytical solution to the Poisson equation in case the density function <em>f</em>(<em>x</em>, <em>y</em>) is analytic in its variables in the polygonal region <em>D</em><sub>1</sub>, and vanishes in <span><math><mtext>D − </mtext><mtext>D</mtext><msub><mi></mi><mn>1</mn></msub></math></span>. By means of this solution the numerical evaluation of the domain integrals in BEM can be avoided.</p></div>","PeriodicalId":100474,"journal":{"name":"Engineering Analysis","volume":"5 4","pages":"Pages 212-214"},"PeriodicalIF":0.0,"publicationDate":"1988-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0264-682X(88)90019-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81898565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Engineering AnalysisPub Date : 1988-12-01Epub Date: 2003-04-03DOI: 10.1016/0264-682X(88)90023-8
Carlos Brebbia
{"title":"10th International conference on boundary element methods","authors":"Carlos Brebbia","doi":"10.1016/0264-682X(88)90023-8","DOIUrl":"10.1016/0264-682X(88)90023-8","url":null,"abstract":"","PeriodicalId":100474,"journal":{"name":"Engineering Analysis","volume":"5 4","pages":"Pages 217-219"},"PeriodicalIF":0.0,"publicationDate":"1988-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0264-682X(88)90023-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89648478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A direct method for equipotential and streamline tracing in the boundary element method","authors":"S.A. Savant, D.D. Reible, J.C. Ortiz, G.Steven Gipson","doi":"10.1016/0264-682X(88)90006-8","DOIUrl":"10.1016/0264-682X(88)90006-8","url":null,"abstract":"<div><p>Presented is a direct method for graphics post-processing of boundary element results in the form of equipotential traces and streamlines. Utilizing a stepping procedure based on the Newton-Raphson method of determining roots, and the boundary integral technique of determining domain field and flux values from boundary data, an algorithm is developed for performing such a task. The method is illustrated in two practical examples involving steady-state ideal fluid flow governed by Laplace's equation.</p></div>","PeriodicalId":100474,"journal":{"name":"Engineering Analysis","volume":"5 3","pages":"Pages 155-160"},"PeriodicalIF":0.0,"publicationDate":"1988-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0264-682X(88)90006-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89232504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Engineering AnalysisPub Date : 1988-09-01Epub Date: 2003-04-03DOI: 10.1016/0264-682X(88)90005-6
N.Gopala Rao , C. Channakeshava , K.T.Sundara Raja Iyengar , B.K. Raghuprasad
{"title":"Elastic and inelastic analysis of reinforced concrete structures using the boundary element method","authors":"N.Gopala Rao , C. Channakeshava , K.T.Sundara Raja Iyengar , B.K. Raghuprasad","doi":"10.1016/0264-682X(88)90005-6","DOIUrl":"10.1016/0264-682X(88)90005-6","url":null,"abstract":"<div><p>A Direct Boundary Element formulation for elastic and inelastic analysis of two dimensional reinforced concrete structures has been presented in two parts. The first part deals with the extension of the Boundary Element Method to elastic analysis of two dimensional problems in reinforced concrete. An initial stress formulation with an iterative scheme has been used to tackle the problem of inhomogeneity introduced by the presence of steel reinforcement which is considered to be smeared over a definite area. The method is applied to the problem of stresses in anchorage zones of prestressed concrete members and singly reinforced beams. Further, it has been demonstrated that the same procedure can be used to solve problems where variation of thickness in the domain occurs. The results obtained compare favourably with FEM results.</p><p>In the second part of the paper, the extension of BEM for elastic-cracking analysis of reinforced concrete structures using initial stress formulation with incremental iterative procedure has been presented. Smeared crack concept and strength-based cracking criterion have been used. Yielding of steel is also considered. The method is applied to examples for which experimental and FEM results are available in the literature. Close agreement has been observed between the results of present analysis and existing ones.</p></div>","PeriodicalId":100474,"journal":{"name":"Engineering Analysis","volume":"5 3","pages":"Pages 146-154"},"PeriodicalIF":0.0,"publicationDate":"1988-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0264-682X(88)90005-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89513872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Engineering AnalysisPub Date : 1988-09-01Epub Date: 2003-04-03DOI: 10.1016/0264-682X(88)90004-4
Yin Jiaju, Ji Xing
{"title":"Numerical computation of dynamic stress intensity factors by the boundary element method","authors":"Yin Jiaju, Ji Xing","doi":"10.1016/0264-682X(88)90004-4","DOIUrl":"10.1016/0264-682X(88)90004-4","url":null,"abstract":"<div><p>The boundary element method for two-dimensional transient elasto-dynamics is investigated. The ynamic stress intensity factors for a centre crack plate with different crack length under a heaviside step loading and blast loading are calculated by the transient dynamic BEM. The results indicated that BEM technique to study dynamic crack problems is an efficient means.</p></div>","PeriodicalId":100474,"journal":{"name":"Engineering Analysis","volume":"5 3","pages":"Pages 140-145"},"PeriodicalIF":0.0,"publicationDate":"1988-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0264-682X(88)90004-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87316930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}