beam with symmetry boundary conditions
beam with symmetry boundary conditions
(OP)
Hello,
I am trying to simulate a straight beam with UDL (linear static), clamped at both ends (u1=0,u2=0,ur3=0).
When whole domain is considered, the results are correct. But, when symmetry boundary conditions are applied (left end: u1=0,u2=0,ur3=0), (right end at x=L/2 : u1=0,ur3=0), the deflections are incorrect.
Can someone point out as to what i am missing here ? Shouldn't deflections in both the cases be same ?
I am trying to simulate a straight beam with UDL (linear static), clamped at both ends (u1=0,u2=0,ur3=0).
When whole domain is considered, the results are correct. But, when symmetry boundary conditions are applied (left end: u1=0,u2=0,ur3=0), (right end at x=L/2 : u1=0,ur3=0), the deflections are incorrect.
Can someone point out as to what i am missing here ? Shouldn't deflections in both the cases be same ?





RE: beam with symmetry boundary conditions
x is normal to your symmetry plane? Have you tried the XSYMM option for the symmetry BC? Maybe the missing UR2=0 is important.
RE: beam with symmetry boundary conditions
yes x axis is normal to plane of symmetry.
Now i have tried with symm/antisymm bc. At left end encastre bc: u1=u2=u3=ur1=ur2=ur3=0,
at right end xsymm bc: u1=ur2=ur3=0. Still the result is incorrect. Correct value of max. deflection is 0.1042,
obtained value is 1.667. what am i missing here ?
RE: beam with symmetry boundary conditions
Upload the model or a similar example if you can't find the reason for the problem.
RE: beam with symmetry boundary conditions
NLGEOM is off.
I have uploaded the file.
http://files.engineering.com/getfile.aspx?folder=8...
http://files.engineering.com/getfile.aspx?folder=8...
Analytical soln. for max. deflection is: qL4/384Dxx, q=1,L=100,E=30*106,H=1,
Dxx=EH3/12
RE: beam with symmetry boundary conditions
When doing it correct, I get the same displacements.
RE: beam with symmetry boundary conditions