I am looking for HDPE 30%fiber material properties for nonlinear analysis.
Stress-strain curve needed and if possible fatigue SN curve also.
Anyone can help me with this?
What temperature? What is the fiber orientation after molding.
I know that fiber orientation and extruding temperature makes diffrence but currently I will be happy with any stress-strain curve data for this material to set my simulation.
Technical data sheet from producer contain:
Tensile Modulus (1mm/min) 1200MPa,
Tensile Strain at Yield (50mm/min) 1,8%,
Tensile Stress at Yield (50mm/min) 27MPa.
Melt flow Rate (190 deg C/ 2,16kg) 8g/10min.
Recommended processing parameters:
Melt temperature 210-275 degC
So we have only one point for stress-strain curve.
Any idea how to get more points?
Well the simple answer is make up some test coupons and test it.
Typically at 30% fibre volumes things tend to be linear to pretty close to failure. The strength at yeild is about 21.6 MPa on that assumption which is cloe the your number of 27 MPa but the strain rates are quite different and it would be expected that the strength would be higher at a higher strain rate.
The infamous vendor data sheet.
DMA (Dynamic Mechanical Analysis) test will give you modulus across the temperature range of interest. ASTM-D4065
The book on DMA by Sepe does not cover HDPE in it's data section.
It is a single test which along with a tensile test will tell you a lot about the material.
As Paul and Bill pointed out, there are all kinds of subtelies in the behavior of plastics, especially reinforced plastics. What kind of analysis are you doing? Short term or long term loads? Impact or Static? What you are looking to find out will have a big impact on what kind of data you need to have for a good simulation.
Is your glass long or short fiber? They behave quite a bit differently.
How is your part being manufactured? Extruded, injection molded, machined from stock?
First I would check with the supplier of the material. They may better data that they don't automatically share. Second I would look for better data from other suppliers with similar materials. CAMPUS has multi-point data on a number of plastics from many suppliers. MatWeb may have better data as well. At the very least you may be able to find comparable data at different strain rates so that you can get a feel for the differences that Bill pointed out. (It cracks me up that the supplier used different strain rates for the yield and modulus data.)
The data is typically given for your normal "dogbone" test sample, so it is limited to in the flow direction.The material is not in the least bit isotropic, usually being much more flexible and weaker in the transverse directions. That makes the analysis much trickier, even if you can get the stiffness and strength in the other directions.
Retrieving data ...