Hello everyone;

 I am Msc student and work on simulation of repairing the cracked steel girders using CFRP in abaqus.

I induce a geometrical crack in steel beam model and exepct it propagate in failure strain path, after increasing the load

I  have a question about crack propagation of steel girder under monotonic loading, what criterion of fracture is suitable for this case?

Crack Propagation Laws Corresponding to a Generalized EL Haddad Equation
M. Ciavarella

Hi,

Assume that we have a composite structure consists of isotropic layers with
a delamination (separation) between the layers. There is a compressive load
applying normal to layers surfaces and hence normal to the
delamination (crack) which closes the delamination, and a shear load tangential to the
crack surface.

the order of shear force is much smaller than the compressive load. can the
delamination propagate du to this shear force?

I mean the pressure is closing the crack in a way that mode 1 can't happen. but
can the shear load induce mode 2 or 3 in presence of such a big pressure?

Thank you all

Title: Structural FEA Intern 

Employer: Schlumberger Technology Corporation

Location: Sugar Land, TX, USA

Starting Date: Available immediately 

Title: Structural FEA Intern 

Employer: Schlumberger Technology Corporation

Location: Sugar Land, TX, USA

Starting Date: 01/01/2011 

Hi all,

 I´m traying to simulate a low-cycle fatigue crack growth in Abaqus 6.9 using xfem. My problem is to add the low cycle method to the xfem solution. 

I believe that the only current option for this would be to manually
create the loading curve and to do the analysis by a brute force
method but i may not be correct in this assumption however.

Please could someone explain a brief method.

i appreciate in advance.

Dear colleagues, this is a paper on the experimental determination of temperature field at the crack tip in a natural rubber using a motion compensation technique. The contribution of the non-uniformity of the IR detectors and the Narcissus effect is taking into account to determine the temperature field.

JB LE CAM

Hello everyone,

 I am having trouble applying cyclic loading in ANSYS with a frequency of 2 Hz while comparing the stress levels of interface elements at my crack interface. After I apply the first loading cycle I post process the result compare the stress values of the elements and proceed to the second cycle, while I do that once I post process the results the time step at the start of the second load cycle starts from time 0 again which is affecting my load increment Vs time, to get around this problem I applied a dummy load until it reaches the time step of the previous cycle and then proceeded with applying actual loads. 

hi am doing my project on high speed machining of aluminium and steel. for chip propagation i want some procedure how to do crack/fracture analysis using ABAQUS. if anybody knew about this please send me information regarding steps involved in building crack propagation.if any practile examples or tutorials are available for this send me to my mail id. my mail id is sasivamsi@gmail.com. am using ABAQUS V6.6.

i will be thankful to the people who help me in this. sice i am running out of time in a week for my project submission i need this.

Dear all,

         I am new to X-FEM, started reading papers a couple of weeks before. I understood, functions[heaviside,sign..] are used to enrich the nodes to simulate virtually the discontinuity and asymptotic functions are used to charecterize the crack tip,other than this regular FEM nodes are there. I have few questions. 

1.what is the role of the asymptotic functions and its unknown co-efficient 'b' in charecterizing the crack tip. What are the parameters do these functions exactly charecterize means wat are the details can we extract from these fns n co-effs?

Prof Jean -Baptiste Leblond (http://www.lmm.jussieu.fr/~leblond/)

kindly invited me to give a seminar at Inst. d'alembert - Paris VI

Hi

I am trying to predict load-displacement curve for concrete cube numerically through ABAQUS. I am just beginer with ABAQUS, I have gone through the concrete material models available in ABAQUS. I found that smeared crack model well suite for analysis. Initially I am simulating a 2D model, I am using plane stress elements with static, Riks options, even I could able to complete the analysis, I am confused how to view the cracked elements and how to plot load-displacement curve.

I want to know whether I am going in a right path by using smear cracking model for crack propagation.

Thank you for your reply

Regards

Gouse 

I am working on crack propagation . I am trying to figure what factors should be taken into account when the crack is being propagated using XFEM.

I am especially interested to know what happens to the additional dof's corresponding to enriched nodes. Once the crack is propagated and crack tip is at new location , we add new dof's corresponding to enrichment functions , but what happens to the information stored by the dof's of previous enriched nodes,do we forget them altotgether , or do we map it to the new enriched nodes?

Hi everyone,

Anyone can tell me how to determine the fracture energy for crack propagation in a 4 points bending notched beam (mode I)?

In fact, in a 4 points bending, there are different displacements: displacement mesured at the upper supports (u), displacement mesured at the midle of the beam (deflection of the beam, f), crack opening displacement (COD), and others ... Among these first two displacements, it's u which corresponds to the mesured force. However, this one includes also bias effect (punching effect = "effet de poiçonnement" in french). So my question is which one of these two displacements must be used to calculate fracture energy?

doi: 10.1016/j.engfracmech.2007.08.012 

<>To describe the crack propagation in a fluid saturated solid I have idea to combine the Strong Discontinuity (XFEM) with the fluid, but at the micro-scale, which probably means to use (Navier-)Stokes equations or some modification of them. <>

Considering the MD (molecualr dynamics) simulation programs, they enable us to define the initial crack and then using different theories they propagate the crack. This process is actually a dynamic feature at least when the sample is going to fail. Here is the question that present in the most modellers assumptions, which will limit the simulation or maybe it is not possible to simulate the process with out these assumptions. One of them which I would like to know your ideas about is the linear velocity which come into conclusions before the simulations start. Actually is this linear velocity remains constant or increase with definite constant acceleration (rate) as crack propagates? I think the answer is No, so why we assume that this theory is accurate?