Research Of Matrix Distributed Computing For Finite Element Analysis Of Drill String Mechanics

Using the finite element method to solve structure statics question, the key is the systemof linear equations solution.Along with structure complication and unit careful division, themethod depending upon the memory solution system of linear equations is not to be ablecompletely to satisfy the request.Therefore, the algorithm studies for solving huge system ofequations becomes a current research hot spot.This article summa rizes the development of Drill String Statics, present situation ofDrill String Finite Element research, and the present situation of researching of C la nguageapplica tion in the Finite Element Analysis.As a base,studies the algorithms of the domesticand foreign using piecemea l thought to solve the Large-scale Linear Finite Element System ofEquations, has studied the piecemea l algorithm and the Wavefront Method which is used bythe large-scale finite element software to transferred the external memory using the memorywith emphasis,at the same time,has analyzed good and bad points of two algorithms. Taking toreduce the element reserves and the enhancement counting yield as the goal,proposes theDistribution Algorithm.It uses One-dimensiona l Variable Bandwidth Storage.When memoringexternal memory document,it transfers specified numbers under triangle matrix compositionunidimensiona l array into the external memory document but like the piecemea lalgorithm,after that, calls the using function to the external memory document to carry onsending in and assigning out,that reduces memory dema nd and node serial numberunreasonable influence. When external memory document memories under triangle matrix,it isunable to solve the system of equations with the common gaussia n elimination.In view of thisquestion, referring to the Improvement Square Root Solution Method, realizes on the one handto transfer the external memory document on the other hand to decompose for modified cholesk y decomposition. After decomposition, puts in the external memory documentagain.Finally, transferres to external memory file for the last reverse back on behalf of thesolution.That realizes the goal that the external memory excha nge time is few and procedurerealization is simple.The Distribution Algorithm has effectively solved the existent problemsof the Piecemea l Algorithm as memory efficiency is low and the serial number rule solution isinsufficient. Takes drill string as the object of study, has established the distributed algorithmprocedure with the C la nguage, studies elastic deformation situation of drill string under ma nykinds of load function, and uses the parametriza tion design la nguage (APDL) of the finiteelement analyze software ANSYS to carry on the simulation for the following short sectionsabove the union place between drill collar and drill rod.Then, has carried on the confirmationto the computationa l procedure.The value experiment proved that, the distributed algorithm has merit of the piecemea lalgorithm and the wavefront method, programming is convenient and the computed results arecorrect.Along with the unit division expanding, the memory efficiency is bigger and bigger,and calculating time changes with the point total according to the parabola rule distribution.The analysis obtains the computation speed of the distribution algorithm is about 4 times ofgenera l algorithm. The algorithm programming which this article realizes has certain theoryvalue regarding the break overseas software monopoly.