# parisa's blog

## Beam on elastic foundation

Dear All,

I am wondering that is there any closed form solution for beam on elastic foundation in case which we have got two stiffness for the springs namely (axial and shear stiffness). The axial force are born because of the some loading conditions in the support.Would you please help me about this?

Thank you,

Parisa

## Fracure mechanics

Hi Every body,

I know that the crack propagation energy release rate G is by defination the release of elastic energy and potential energy of loads per unit area of crack extension and for a linear body loaded by a single load P is given by :

G=P^2/(2b)*dc/da

Any body know if instead of load P, moment M is being used what would be formulation?

I really need this one

Thank you,

Parisa

## Cohesive elements parameters

Dear All,

I modelled a beam with a hole and used cohesive elements on the possible crack plane.

When I run the model in 2D, it works very well and I can get the results pretty good.

Why running the same model in 3D (making 3D model and running it) has caused me a headach for a long time and I can not

get the results?

Any idea highly appreciated,

Thanks,

Parisa

## Tension in screw because of moment in section

Hi,

In a section of a beam with a rectangular hole which has got crack (see attached picture); Moment and shear are specefied. I can undrestand why we have tension in the screw because of the shear but why do we have tension because of moment in the screw? Can anybody explanin me why moment in the section can cause tension in the screw which should be accounted for in the screw design.

Thank you,

Parisa

## Stiffness of a beam

Hi,

As a part of my research, I would like to break down a simply supported beam to two beams shown in the attachement.  I expect to remove the bond and use of springs for transforming deformation of upper beam to lower beam. What could be the stiffness of springs which could be used in new model?

Thank you for your comment,

Parisa

## Solution for beam on elastic beam

Hi,

I am looking at some deformations in beams.  I have an elastic beam sleeping on another elastic beam and connected via springs that have two dimensional stiffness. Anybody knows how should I go for closed form solution of this beam and obtain deformations in springs??? I can model it in sap2000 or ABAQUS and solve it at there but I am now looking for only closed form solution... Besides, I am looking for deformations in spring caused by applied load. I have attached a sketch of my model. Any idea or comment will be highly appreciated.

Thank you for your comment,

## Analysis of beams with hole

Hi everybody,

Is there any limits for using of LEFM?  I have modelled a beam with a penetration.I have moved the holes vertically in the beam and obtained the stress intensities for each movements at the corners of the hole. Now the hole is closing the edge, stress intensities in mode I and II, suddenly change values (positive to negative and vice versa)  what does this mean ?... Does it mean that I should limit my movements?,,,,

Thank you,

Parisa,