Hi, I am trying to use Johnson Cook model for predicting equivalent flow stress. Just to check its validity at extremities, I input ductility as plastic strain, but I don't see it output stress close to ultimate tensile strength. I used ductility over 1 millisecond to calculate plastic strain...
Hi, I am thinking if it is possible to simulate crack growth under High Cycle Fatigue in Abaqus? All the tutorials I have come across on XFEM shows crack growth only with static load. Wondering if there is a way to simulate alternating stresses superimposed on static stresses.
Thank you
Geoff
Hi,
I am looking for various methods by which one can idealise a fillet weld joint in FE analysis. I searched through previous threads here and some general search on Google. Didn't find relevant info.
Currently I use bonded contact between solid bodies which are welded. Then (as I get...
Apparently this is a bug in Ansys Workbench V14, which is corrected in V15. Workaround in V14 is to explicitly drop the midside nodes for beam / shell elements (for thermal analysis). Also for solid elements in the model, midside nodes should not be 'kept', but set to 'program controlled'.
Hi,
I am doing a steady state thermal analysis in a model which has solid and beam elements (using Ansys Workbench 14). I get an error "Higher order elements are not valid for current analysis". But this problem is not there if I suppress the beam elements (even though the solid elements have...
Hi,
Are certain fatigue criteria more relevant for certain type of materials? I heard that Gerber is good for ductile materials, etc. So can we use criterion based on material? Any particular reference on this?
Thank you
Geoff
Hi Orel,
Thank you for the reply. I had a try with Bushing joint. It worked! I have not tried Matrix27, but my colleague said its function is similar to that of bushing joint as far as assignment of stiffnesses and damping are concerned.
Geoff
Hi,
I would like to connect surfaces of two bodies with springs in 3-directions (X,Y,Z) in ANSYS software. As the surface normals lie only along Y-direction and that a spring accepts stiffness only along its longitudinal axis, I am wondering if I can use Bushing Joint instead and define...
Hi,
I am doing non-linear static analysis of a spring like structure. As the solution convergence is quite difficult, I would like to know what parameters for automatic stabilization - damping factor or dissipation energy fraction - should be given for convergence. And what are the criteria for...
Thanks btrueblood. This answers the question! Yes, the structure is vibrating and loading is applied at an angle causing possible shear forces in the rubber.
Kind regards
Hi,
I have a neoprene rubber sheet mounted on a structure. I am getting FRF using impact hammer testing and measuring damping through half power point method.
When I compress this rubber sheet with two different loads I am getting different damping values. Higher compressive load gives more...
Yes, but theoretically one should add damping also along with mass to damp out the split modes caused due to tuned mass. So I am looking to add damping tape which has highest loss factor in that frequency zone of 16kHz.
Thank you for all the responses.
Presently I am using 3M ISD 112 tape whose loss factor droops to 0.3 by 10kHz. It's greatest loss factor is around 1kHz.
It is not a shock event, but a forced vibration at 16kHz.
Demon3 - Can you please explain what you mean by 'higher mass is good too'. Do...
Hello all,
I would like to know if there is any viscoelastic material that is more suited or designed to damp high frequencies - 15000 - 16000 Hz ? I mean having loss factor near to 1 around this frequency range? Most of the commercially available tapes are designed for 1000 Hz range.
Thank...
Hi Dan,
I work on a research project on damping machining vibrations. Presently the component which the industry gave is being machined at reduced parameters due to forced vibrations and hence consequent problems such as heavy vibrations, noise, etc. My task is to design some damping solution...
electricpete - many thanks for clarifying to my confusing question. You guessed right. My forced vibration frequency is between two resonant frequencies. So I don't know how to define this - stiffness or mass based because it changes with respect to the frequency I consider. Hence that question...
Hi Tmoose, thank you for providing me with the article.
As I said earlier there is no instability in the process. Only strong forced vibration.
I checked the book which you said. It has short discussion on minimising impulsive forces on machine tool structure for which they suggested...