Tensile Strength & Resin/Ash Burn Off Questions

Could anyone please steer me in the right direction to find resources on data for Ultimate Tensile Stress numbers and weight sample ( before /after burn off ) numbers/ percentages ?
Is there a normal range for UTS in ksi for a fiberglass sample 6-7 mm thick , not cored , hand laid and polyester resin used ?
Is there % ranges for Ash content for a coupon burn off ? How to tell if resin rich or resin shy ?
Thank you in advance .

 

Not such an 'easy' answer to that one. Since it, as always - depends.
It depends upon the resin, the glass used, its direction, it is hand lay up or vacuum etc etc..and as such values can range from circa 100 MPa to 700MPa.
Without knowing what the laminate schedule is, it is hard to say whether the values you have are representative of the values that are expected for that laminate schedule.
As such those numbers are - well - just that, a series of numbers.

 

Thank you for the reply .

 

Before you attempt to reverse engineer the properties of the laminate by testing samples and burn off test, familiarize yourself with the LR or ISO formula for predicting UTS of a laminate.

Do not be intimidated by the equation as some are in easy to follow quadratic form. LR or ISO formula for UTS are close together and should not be a problem.

The UTS formula are based on the MINIMUM properties of the material used (fiber and resin) and some hints or is specific on the compatibility of the "appropriate" resin to fiber use. The glass content/resin content ratio are also based the method of construction, that is Hand layup or Vacuum assisted. You may have to consult other books for approximate glass content achievable for different processes,

Remember, the formulas prediction is based on MINIMUMS and as such, the resulting UTS is rather "conservative". To predict UTS with a specific resin and fiber in mind, there are other more complex method and complicated math plus a myriad of material properties required for the equation.

 

Report your data here and see what rx says can be inferred. It isn't going to throw him off.

 

You should have been able to pretty accurately assess what that laminate consisted of, by visual inspection, and attempting to prise it apart .

 

For a start, what is the lamination schedule, the types of fabric used, and the resin used?