I have tested 5 specimens for tensile strength of GFRP. I want to know what is the maximum variation is acceptable ( what will be deviation allowed)
This is basically in-line with the test standard followed....generally 5 is sufficient as per ASTM. Checking for repeatability from another set of samples is always beneficial.
Hi, Manjunath,
For GFRP, you can test the matrix first only, then GF
Dear Manjunath,
Roughly speaking, the deviation allowed should not be higher than 10%. However, this will also depend on many factors. First, the length of your fibers (long continuous or short ones). Additionally, when working with fiber reinforced materials, the orientation of these is critical since it induces an anisotropic mechanical behavior of your material. Thus, if you want to validate the repeatability of your results, you must take your samples with same orientation. Otherwise, you are likely having a different values of your modulus depending on your fiber orientation.
Best regards
The strength of composites can be described by the Weibull distribution function.
That is to say that the strength of composites is a statistical function.
To obtain the parameters of the Weibull function one needs at least 15 measurements.
However, the deviations allowed in practice can be found within the ASTM that are prescribed for materials having specific destinations in service.
- Badges
- Science topic