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material model for simulation of glass machining

Submitted by farzad pashmforoush on

Hello every body

I am working on the simulation of micromachining of “glass” in abaqus.

Although the glass is brittle, it shows some plasticity in micromachining

because of the high hydrostatic pressure field present in the machining region.

Now I am looking for an appropriate material model for glass with

elasto-plastic behavior which allows element deletion. I am not sure if "johnson-Holmquist damage model" is suitable for machining simualtion or not? I would be very thankful

if anyone would please help me.

With best regards

Farzad

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shzangeneh

i think the best way to simulate damage is johnson-cook model for high velocity case and also when we want to simulate machining process and this model is base on stress triaxility and also it can be used with johnson hardening method

Sat, 06/01/2013 - 09:38 Permalink
farzad pashmforoush

Dear shzangeneh

thx vey much for your reply. The micromachining process that i want to simulate is not under high strain rate. so, do you still think that johnson-cook model is suitable for low strain rate conditions? if yes, how can i find the parameters of this model for glass.

thx very much for your help

Sat, 06/01/2013 - 16:28 Permalink
shzangeneh

Idon't think so! as u may know johnson function contain three part as follow

flow stress=(a+b(strain)^n)(1+c*ln(strain rate))(1-T)

as you can see strain rate and also temperature is very influential in this function so regarding your question i think when u works with low strain rate i doesn't work

you can find the parameters by doing some expriment such as tensile test in different temperature and also for finding the parameteres used in johnson damage model d1,d2 and d3 you must find stress triaxility 

 

Sun, 06/02/2013 - 05:21 Permalink
farzad pashmforoush

Dear Zangeneh

thx very much for your attention to my problem. do you have any offer for me to choose another material model for glass which shows some plasticity under high hydrostatic pressure?

what do you think? can i use "drucker-prager" plasticity model with ductile failure criterion?

with best regards

Sun, 06/02/2013 - 06:23 Permalink