Recent content by futura22

Hello everyone... I am performing a postbuckling analysis on a compressed cylinder. I've done a linear buckling analysis on perfect cylinder to find the eigenvalues, then would like to use the *imperfection command to introduce the imperfections on the cylinder. My question is, which line...

okay, one more thing...from what i understand the LPF is the ratio of load/critical load. Does multiplying the LPF with the critical load obtained from eigenvalue analysis will give the actual critical load?

Basically for eigenvalue analysis, I specified concentrated force of 1500 on 2 nodes and 3000 on other 2 nodes. That means the total forces applied are 9000. This is what been done in the ABAQUS Benchmark documentation input file and I tried to imitate them in my model. I then multiply the...

Ok. How to find the bukling load? Do you meant plotting load proportionality factor(LPF)-deflection graph and then multiply the highest value of LPF with the applied load? If it so, the LPF should always be smaller than 1 for it to be theoretically correct, is it?

how about using a curve shell. Is it still be force or force per unit length?

i have tried specifying different combinations of eigenmodes from using a unique mode to combination of all eigenmodes but still i got a value of LPF(Load propotionality factor) higher that 1. That means the critical load afer introducing the imperfection is higher than perfect cylinder which...

great! thanx a lot...

Currently i am running a load-displacement analysis for buckling of cylindrical shells. The first step is introducing imperfection on a perfect cylinder and requires combinations of eigenmodes from linear eigenvalue analysis in order to find the critical loads. My problem is I do not know how...

Does anyone know the unit of concentrated force? Is it force per unit length? Thanx

what do u guys mean by normalised?

yeah i have plot one and it looks nothing wrong in terms of the way it buckles... i am running eigenvalue buckling analysis for cylindrical shell i am comparing both from the abaqus manual and the theoretical result...but what confusing me was the 'very small' value of eigenvalue obtained...

Thanx for the reply, yes..the lowest eigenvalues that I got are no where near the results. So assuming the input files in the ABAQUS is correct, I am just choosing the value which give the closest to the correct answer, that means not neccessarily the lowest one.Is it okay to do that? I have...

hello everyone... I am running an eigenvalue buckling analysis from input file from abaqus documentation. The outcome of the linear analysis is series of eigenvalues and they will give me the magnitude of buckling load by simply multiplying with the applied load. my problem is how i am going...

hmm quite weird coz I could open the website through the link...anyway you can search thru google "ABAQUS documentation ". Then choose ABAQUS Benchmark manual once you managed to open the main page. Thanx for your time. I really appreciate it

Just go to 1.analysis test -> 1.2 buckling analysis -> 1.2.3 Buckling of a cylindrical shell under uniform axial pressure ABAQUS documentation 6.6: http://abaqus.ethz.ch:2080/v6.6/books/bmk/default.htm