How do I define the failure criteria?

LOAD DISPLACEMENT CURVES Stiffness increasing in ANSYS non linear analysis. HOW CAN I CORRECT IT?

Hi. I am doing non linear FE analysis using a new material beam under flexural 2 point loading using ANSYS. I have defined a bilinear material model. The solution has converged. In results I am...

01 March 2021 9,911 3 View

Is anyone familiar with the cyclic compressive fatigue testing (BS EN 12697 - 25) ?

I would like to get more information on the cyclic compressive fatigue testing (BS EN 12697 - 25) which is typically done for bituminous material in pavement design. Any one can advise on the...

28 February 2021 2,004 3 View

For modelling epoxy-based matrices (in composites), which model in ABAQUS is the most suitable, Concrete damaged plasticity or Drucker-Prager model?

I am working on developing a micromechanical FE model for predicting kink-band formation in UD composites. To model matrix plasticity, which model, out of Concrete Damaged Plasticity and...

28 February 2021 5,415 1 View

Why am I getting 'Infinity' and 'NaN' in my mixed-mode energy release values?

Hi everyone, I am currently running a mixed-mode simulation of a DCB using a user-defined cohesive zone model (UEL), however, the results I am getting don't make sense. I used the same UEL for...

24 February 2021 4,157 1 View

Why does the sum of reaction forces not match the force component of a Free Body Cut in Abaqus?

I am using Abaqus to simulate a plate with in-plane loading. The boundary conditions allow the right edge to move up and down, the displacements on the left edge are fixed. There is no rotation...

23 February 2021 711 3 View

Are there methods for automatically mapping floodplains, fans and terraces?

I want to map these river geoforms with as little subjectivity as possible. I have a high resolution DEM generated by drone data.

22 February 2021 7,800 3 View

How can misfit between business requirents and ERP system business process be reduced?

One main reason for failure of most ERP implementations is the misfit between business requirents and ERP system business process be reduced. How can the misfit between business requirents and ERP...

22 February 2021 5,709 5 View

The most suitable method to calculate the stress intensity factor in the presence of contact between the crack lips?

I'm trying to study cracked structures under a compressive load taking into account contact between the crack lips. I would like to know if the method of extrapolation by displacement remains...

21 February 2021 8,694 4 View

How can I obtain Reaction Forces in ABAQUS?

I am trying to simulate a simplified version of a beam resting on 10 points using Abaqus. The solutions I want to obtain are the Reaction Forces in each resting point or area when applying a...

21 February 2021 3,075 2 View

Can I arbitrarily take a cycle number of 40 for the gene that was not expressed at all in qPCR results calculation?

I ran RT-qPCR for a control and a treated group and it appears that my gene of interest was not expressed at all in any of the subjects in the control group. So I was wondering if I could...

20 February 2021 6,243 10 View

Kumarswamy Karpanan

My suggestion is don't use the default fatigue analysis from any software.

First identify the critical locations on your model and then extract stress / strain on those locations. Then identify fatigue analysis method and fatigue curve that is applicable to your loading and component. If any standards or codes (EX; ASME, API, DNV etc) are used in the design and analysis, use the fatigue analysis methods and curve from those standards. Collect/estimate the loading histogram for your component and run the fatigue analysis and calculate the damage. Use appropriate design factor or Factor of safety and estimate the final life. Then you can equate displacement with the failure.

I have simplified the fatigue analysis procedure generally used in the oil and gas industry or high pressure vessel industry.

Giovanni De Morais Teixeira

As far as I remember the ANSYS Fatigue Tool can't be customized. It is a very simplistic/basic and outdated (as far as I know) tool. You'd have to switch to nCODE or fe-safe in order to do so.

Akshay Kalyana Kumar

Thanks for your valuable suggestions Kumarswamy Karpanan and Giovanni De Morais Teixeira

Bart Kemper

You need to assess what is your most likely failure mode before analysis. Regardless of the mode, you need to have some additional method to go with FEA such as traditional calculations and stress concentration atlas look-ups.