Recent content by TheBigM

I'm not familiar with that particular product but it is not described as an adhesive but as a filler. How are you curing the EC 3524? If you're using a vacuum bagging method then the vacuum may pull out volatiles giving you voids. If you're curing at ambient pressure then you might want to...

You could try Micro-Flexitronics (http://www.mflstraingauges.com/). They offer a large variety of strain gauges and also will make them to your requirements if needs be. They're cheaper than VPG and delivery is usually less than two weeks. You'll still need to get your adhesives from VPG though. M

Hi, have you been able to evaluate the impact damage area? You'll need some sort of NDT capability to do so but it might help to explain the results you're getting. The fibre size and interaction with the matrix might lead to differing amounts of impact damage. M

If they've used strain gauges for the determination of modulus the adhesive may have softened under heat and moisture allowing the gauge to creep more slowly than the actual sample itself. There's always the possibility that they've used an extensometer at RT (to save money on gauges) and...

Thanks for the comments guys.

Some time ago I read a paper which discussed the relationship between ILSS and tensile strength in that to a certain extent ILSS goes down as tensile strength goes up and vice versa. Can't remember the exact content now and so I'd like to re-read it but I can't find it. Does anyone know of a...

Thanks for the information. By the looks of it the Hexcel HP655 is the best choice. Thanks again. M

I have to carry out tensile testing at 210°C. The maximum cure temperature of my composite will have been 240°C. Can anyone recommend a good adhesive for bonding tabs and testing at this temperature? M

Urethane sheet every time. The marks cut by the blade virtually disappear after the blade has passed. I would advise against glass simply because you can get sparks from the blade (not good in a static sensitive environment) and also its easy for the blade to slip on the surface creating a...

Many thanks for your replies - I kind of figured that the edge finish would be no good for testing. Thanks again.

Anyone have any idea what (if any) damage or degradation is caused by water jet cutting of monolithic composite plates? Water jet cutting is being suggested by some people for cutting of test specimens but I am concerned about the idea of blasting high pressure water at a composite. Does it...

That's great, thanks guys. I've just managed to locate the method in ASTM and they concur with yourselves. Thanks for answering so promptly. M

I have to perform some hot/wet testing of compression strength after impact specimens and would appreciate opinions on when the damage should take place. Should it be before or after conditioning? What is the most common choice? Its something that is hard to find answers to. This is pretty...

It's actually an open hole compression test. I suspected that the orientation would not have a dramatic effect at either 0 or 90 but a colleague disagrees. I had thought that the isotropy was the same and so any edge effects etc would be too small to be detectable. After all you have the same...

Thanks SW, further to this, which configuration will give the highest compressive strength? (+45,0,-45,90,+45,0,-45,90,90,-45,0,+45,90,-45,0,+45) OR (-45,90,+45,0,-45,90,+45,0,0,+45,90,-45,0,+45,90,-45) Thanks.