Fracture mechanics Definition and 17 Threads

So I am trying to find the amount of energy needed to break apart stone into different sized chunks (when either punching it or blowing it up) and I'm using this method to estimate it: Assume the object got broken up into cubes of the desired diameter Find the surface area of all the cubes...

I did my derivation for a beam as shown with Young's Modulus ##E##, width ##w##, crack length ##a##, and surface energy density ##\gamma##. I understand that a crack will propagate when the free energy ##G## decreases with increase crack length ##a##. Free energy is the combination of the...

Hello everybody We saw a fracture in a switch rail, now we're trying to find the reason, may be you can help us. This rail is made of R260 steel. Let me know if any other information is needed. I have attached pictures of this rail. Thanks in advance

I've been giving this some thought. It's clear that the stiffners will increase the resistance of the material so that the energy release is no longer high enough to cause further fracture. I'm just not sure what formula I can use to take into account the new resistance. I suspect part 1 of the...

I am trying to prove the superposition principle of stress intensity factors (SIFs). The superposition principle states that the stress intensity factors obtained from the boundary loading are equal to those obtained from the crack face traction loading. I used a flat plate model with the size...

Hello all, It seems like a fairly straightforward question but I cannot find any information in the literature. Let's suppose we apply a crack driving force K1=45 MPa.m^0.5 to a notched specimen with an upper shelf fracture toughness K_mat = 50 MPa.m^0.5 at room temperature T0=20 oC. Under a...

I am new to COMSOL and I want to model fluid flow in stress field. As starting point I want a simple 2D box having a fracture from right to left while pressure gradient vertically. I want to know the threshold value of that pressure from top which allows flow of fluid in fracture. Can anyone...

I had posted this in the General Engineering forum but perhaps it is a better question for mechanical engineering forum: 1) Consider a centre crack specimen subjected to a wedge load a shown in the figure: https://www.physicsforums.com/attachments/centre_crack_wedge_load-jpg.112584/ In such a...

Hello everyone, I am currently doing my masters research project on fracture mechanics. My problem is such that I have a flat circular disc(brittle) which is simply supported around its circumference. The top surface of the disc is subjected to a point load at its centre. the bottom surface has...

I am looking to determine fracture toughness for aluminium, from a punch test. I have the dimensions of the specimen and the load-displacement curve of the test. I have seen how to calculate Kic for brittle materials from a punch test but am struggling to find a formula for ductile materials...

Hi everyone, I have a problem that I hope someone can help me with, the question is. A mass of 500kg induces a tensile stress in a glass sheet restrained at the top. Given that the fracture strength of sound glass is 170MPa what is the maximum length of slit that can be tolerated without...

Hey everyone, Im having some major trouble with an assignment that I just can't figure out what to do with it. we have been given a pump jack similar to below: http://en.wikipedia.org/wiki/File:Pump_Jack_labelled.png Ignore the belt attachment and gearbox, ours just has motor to...

I am having trouble understanding where the units to fracture energy come from when worked out with the following equation. 2\gamma_{ef}=\frac{K^{2}_{Ic}}{E} fracture energy = fracture toughness/young modulus i asked my teacher as this is part of my coursework but he was not able to...

I am curious if anyone here is familiar with ABAQUS and using it for crack propagation. I am doing a project on fatigue life and need to use a computer program (ABAQUS is our FEA) to predict fatigue life under specific loading conditions. I am planning to use crack propagation to do this and...

Hello, I was wondering if someone could clarify the major differences and limitations of Damage Mechanics and Fracture Mechanics. I'm more familiar with the fracture mechanics approach, but have never done any damage mechanics before. I'm just trying to sort out in my head how fracture...

I am trying to determine the critical crack length of a part using finite element analysis. The software I am using (ABAQUS) has the ability to perform fracture analysis. I model the part, create a crack, and ABAQUS will output the stress intensity factors (modes I, II, and III) and contour...

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