Hi, I have a sheet of open cell pure iron foam (porosity> 90% , thickness around 2.5 mm), and I would like to prepare 1 cm x 1 cm samples for subsequent compression tests. My foam is ductile and also it can be easily squeezed or bended with hand. I was wondering if I use a big rotatory saw (Bosch 4310, picture attached) to cut long rectangular strips (cuboids) of the foam (20 cm x 1 cm), could it significantly change the mechanical properties of the whole foam sheet, or it would change the mechanical properties of the cutting surface only. I would use the saw only to prepare the cuboids as the first step of the sample preparation. As the second step, I would cut the rectangular strips into 1 cm x 1 cm cubes using a small rotatory tool (Dremel) and a holding gadget. It is important for me to keep the consisteny between the properties of my samples. I would appreciate your input.

Regards,

Reza

I am investigating the effect of different structural properties on mechanical behavior of open-cell foams using compression tests. The structural properties that I have been considering are cell size, pore size, strut thickness as well as relative density. I am struggling on which surface area to consider for calculating the compression stress values, the "apparent" area which contains struts and pores (calculated by external dimensions of the specimens) or the "real" area which contains the struts only (and not pores). I wonder if the difference between the stress responses of two foams when the "real" areas are taken for stress calculation would be similar to the difference between the stress responses when "apparent" surface areas are taken to calculate the stresses. Don't you think taking the real areas (struts only) better reflects the difference between the mechanical responses of two foams with different structures? Are stress values calculated by the "apparent" area_ while the "real" areas are different_ comparable at all?

Thanks,

Reza

Hello,

I would like to know how to measure the density of open cell porous iron foam. I am studying the mechanical behavior of pure iron foams for which I need to compare the relative densities of different foam samples. Could the density of the foams be simply calculated by the mass over the bulk volume (volume of the struts + volume of the pores) of the foam? Can I use Archimedes principle to calculate the foam density given that I have open cells? What is the best method to calculate the foam density?

Best Regards,

Reza

Hello

I am actively looking for a PhD in Bio/Biomedical engineering. I am interested in multidisciplinary applied research, and would prefer to work in a research group of multiple expertise.

I have recently finished my (course-based)Master of mechanical engineering at the University of New Brunswick, Canada (I completed my BSc at UNB too). My academic background is solid mechanics, and I am experienced in Finite Element modeling and 3D image reconstruction from MRI/ CT data. Over the summer of 2015, I was working at the UNB Institute of Biomedical Engineering. For my Master project, I conducted an experimental biomedical project which involved human subjects. I have completed the following graduate courses : Continuum Mechanics, Fracture Mechanics, Micromanufacturing, Biomaterials, Basis of Biomedical Engineering.

Attached please find my CV and feel free to contact me for further information. Please reach me at reza.alavi@unb.ca.

Regards,

Reza Alavi

Hello Everyone,

I recently started to do a project on a FE knee model. Right now, the only available software for me is SolidWorks which was originally purchased for CAD modelling. I was wondering if anyone knows whether SolidWorks FE feature is "good enough" for analyzing a knee model (and for other tissues just in case), or you recommend me to push my supervisor to purchase a license of a "Real" FE software such as ABAQUS. If you have any experience of FE modelling of tissues,bone,etc. I would appreciate if you help me out.

Thanks,
Reza

Hello Friends,

As you may noticed, once you use ductile damage criterion in Abaqus, you need to enter Fracture Strain, Stress Triaxiality and Strain rate as your inputs. It seems confusing to me as in the manual it is mentioned that "the [ductile damage ] model assumes that the equivalent plastic strain at the onset of damage is a function of stress triaxiality and strain rate", while in the interface you need to enter Fracture strain as your input along with stress triaxiality and strain rates. I tried to find the aforementioned function but I had no success in it. I was thinking may be there is no predefined function in Abaqus for Ductile damage model, as opposed to other damage models in which the strain at fracture would be obtained as an output of a clear function such as Johnson-Cook damage model, and maybe Abaqus only interpolates a function based on the tabular points we introduce as Fracture Strain, Stress Triaxiality and Strain rates. I would appreciate if you help me to find an answer for this question and tell me whether Abaqus uses any predefined function for Ductile Damage model or not.

Regards,

Reza

Hi,

Is that possible to define an INTERIOR surface in Abaqus???

Hello ,

I am working on a project using abaqus to
simulate miling process. As the first stage, I have to be able to simulate cutting process in Abaqus. I have looked up Abacus 6.11 documentaion a lot but did not find too much of usefull information. Could any one kindly give some hints how to develop such model or introduce me some usefull complete resources?

Regards,

Reza