pengweicai 发表于 2007-9-30 18:31:53

无单元伽辽金法程序

一维的程序代码,分析模型为杆,采用matlab程序

% ONE DIMENSIONAL EFG PROGRAM
% SET UP NODAL COORDINATES ALONG BAR, DETERMINE NUMBER OF CELLS
x = ;
nnodes = length(x);         
ncells = nnodes-1;
% SET PARAMETERS FOR WEIGHT FUNCTION, MATERIAL PROPERITES
dmax = 2.0;
E=1.0; area=1.0;
% DETERMINE DMI FOR EACH NODE
dm = dmax*(x(2)-x(1))*ones(1,nnodes);
%SET UP GAUSS POINTS, WEIGHTS, AND JACOBIAN FOR EACH CELL
gg = zeros(1,ncells);
jac = (x(2)-x(1))/2;
weight = 2;
gg = -.05:.1:0.95; gg(1) = 0.0;
% INITIALIZE MATRICES
k = zeros(nnodes);
f = zeros(nnodes,1);
GG = zeros(nnodes,1);
% LOOP OVER GAUSS POINTS
for j = 1:length(gg)
   xg = gg(j);
% DETERMINE DISTANCE BETWEEN NODES AND GAUSS POINT
dif = xg*ones(1,nnodes)-x;;

% SET UP WEIGHTS W AND DW FOR EACH NODE
clear w dw
for i=1:nnodes
drdx = sign(dif(i))/dm(i);
r = abs(dif(i))/dm(i);
if r<=0.5
w(i) = (2/3) - 4*r*r + 4*r^3;
dw(i) = (-8*r + 12*r^2)*drdx;
elseif r<=1.0
w(i) = (4/3)-4*r+4*r*r -(4/3)*r^3;
dw(i) = (-4 + 8*r-4*r^2)*drdx;
elseif r>1.0
w(i) = 0.0;
dw(i) = 0.0;
end
end
%SET UP SHAPE FUNCTIONS AND DERIVATIVES
won = ones(1,nnodes);
p = ;
B = p.*;
pp = zeros(2);
A = zeros(2);
dA = zeros(2);
for i=1:nnodes
   pp = p(1:2,i)*p(1:2,i)';
   A = A+w(1,i)*pp;
   dA = dA+dw(1,i)*pp;
end
Ainv = inv(A);
pg = ;
phi = pg*Ainv*B;
db = p.*;
da = -Ainv*(dA*Ainv);
dphi = *Ainv*B+pg*(da*B+Ainv*db);
%ASSEMBLE DISCRETE EQUATIONS
if j == 1
   GG(1:3,1) = -phi(1:3)';
else if j>1
   k = k+(weight*E*area*jac)*(dphi'*dphi);
   fbody = area*xg;
   f = f+(weight*fbody*jac)*phi';
end
end
end
% ENFORCE BOUNDARY CONDITIONS USING LAGRANGE MULTIPLIERS
q = ;
m = ;
% SOLVE FOR NODAL PARAMETERS
d = m\';
u = d(1:nnodes);

pengweicai 发表于 2007-9-30 18:36:04

二维的程序代码

二维的程序代码

jonewore 发表于 2007-10-1 19:39:10

能介绍一下什么是无单元法吗?

pengweicai 发表于 2007-10-3 09:42:41

无单元法是众多无网格方法中较有代表性的一种,形式简单、明确,计算精度高。因其具有仅需离散的
结点信息、解答具有高次连续性、能较好地反映应力高梯度分布并便于跟踪裂纹的扩展过程等优点,无单元法自
问世以来获得了广泛的重视,已成为计算力学领域的一个研究热点。

具体的可以看看下列文献:

周小平,周瑞忠.无单元法研究现状及展望.工 程 力 学,2005,22(1):12-20
黄岩松; 周维垣;三维无单元法及其工程应用,水力发电学报,2005,24(6):14-19






附件是 一维和二维的 介绍,以及怎样编程。

wishes188 发表于 2007-10-25 21:34:57

最近在研究这方面   非常感谢

youxiangltn 发表于 2007-11-29 18:04:50

thank you

swf00706 发表于 2007-12-8 21:38:52

很想和大家一起交流无望各方面的知识
qq:36641420
群号码:3766263

swf00706 发表于 2007-12-8 21:39:50

很想和大家一起交流无望各方面的知识
qq:36641420
群号码:3766263

visualheart 发表于 2009-12-6 01:58:43

好东西,谢谢

visualheart 发表于 2010-1-31 17:29:04

谢谢分享,谢谢分享

visualheart 发表于 2010-4-17 12:33:58

下载学习,谢谢分享

fyhgit2008 发表于 2010-5-21 12:54:25

谢谢,学习学习
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