Bearing hole strength
Bearing hole strength
(OP)
I am planning to do bearing hole strength of carbon fiber laminate coupons as per ASTM D5961.
The standard recomends to use coupons having 0.25 inch hole and same diameter pin, with Width/Dia ratio 6 and edge/dia ratio 3.
Now my big doubt is that, for a given thickness of a laminate, Is the bearing hole strength is a constant? I other words, Is it independent of the diameter of the hole? If I test the same laminate thickess with big size hole (0.5 dia) will I get same bearing strength from a coupon with 0.25 dia hole (provided if I keep the W/d ratio and E/d ratio same)?
Appreciate, if composite experts thro some light on this.
The standard recomends to use coupons having 0.25 inch hole and same diameter pin, with Width/Dia ratio 6 and edge/dia ratio 3.
Now my big doubt is that, for a given thickness of a laminate, Is the bearing hole strength is a constant? I other words, Is it independent of the diameter of the hole? If I test the same laminate thickess with big size hole (0.5 dia) will I get same bearing strength from a coupon with 0.25 dia hole (provided if I keep the W/d ratio and E/d ratio same)?
Appreciate, if composite experts thro some light on this.





RE: Bearing hole strength
I think the intent with these minimum ratios is to allow you to actually test what you THINK you are trying to test. Violate these guidlines and you need to make sure you are actually seeing the proper failure mode for the strength number that you are trying to derive.
I don't think I've explained this very well, but hopefully you get my meaning...
RE: Bearing hole strength