I'm not at all familiar with phosphoric acid anodizing, but apparently, I'm going to need it as a final process for surface preparations involving adhesive bonding. The problem is that I neither need it nor want it in other areas that do not involve bonding - it obviously involves dipping the...
Thanks for the reply rb1957.
The PSD is not associated with gust - it's vibration. The static loads established from aero and inertia were ultimate loads.
Have you ever seen someone add static load results to 3Sigma loads? In other words….say I exposed a structure to some aerodynamic and inertial loads and then obtained resulting fastener loads. Then I exposed the same structure to a power spectral density curve and obtained resulting fastener...
I was wondering if someone could give me some free FEMAP tech support as my access to Siemens has lapsed. The question goes like this: I can successfully complete a solve for a laminate structure’s normal modes (#2 Normal Modes/Eigen Value), followed by a solve for the modal frequencies (#4...
Yes - it's indeed air and a very violent environment. The overall sound pressure level (OASPL) for the frequency spectrum is 164.2 dB. How is the OASPL value calculated using the data of the frequency spectrum?
thanks Greg.
Thank you Greg.
I am reading this report and it says that 144.6 dB at 400 Hz converts to an equivalent 3-sigma pressure of 2.11 psi. That doesn't seem correct. Thoughts?
v/r,
msn
I am not well versed in acoustics so bear with me......
I am reading a report that presents an acoustic noise chart whereby a range of 1/3 octave sound pressure vs a frequency range is plotted. The report states a "worst case" value (dB) at a specific frequency and goes on to say that this can...
Something that I've never had a good grasp on was how to determine when I would need a supported or un-supported film adhesive. Is the carrier only used to maintain a consistent bondline thickness? When should one choose a knit vs random carrier?
thanks,
msn
Yes, you guys are correct. There is always usually some darkening. It just seems a little excessive this time. I want to be able to prove to my customer (and to some extent- myself) that all is still well. I think the idea of just creating some panels with proper thicknesses for SBS and varying...
SW,
The resin is cyanate ester so you can imagine what kind of an item i'm dealing with here.
The production cure temp is 350F with a 400F post cure.
The repair cure temp was 350F with no post cure - only 90 minutes.
The area around the repair looks to be on the verge of charring. I've worked...
I agree that the act of bonding doublers to the specimens and thinking that the skin will experience interlaminar failure during a test is kind of a pipe dream. I'm not sure it's even work attempting. I do have access to every type of Tg testing nevertheless, I do not see how I can use Tg to...
SW, I should have clarified my intentions a little better. I'm looking at this from a strength perspective. I have a repair that must be carried out on some skin. The repair was performed remotely using a portable hot bonder unit. The person that performed the repair assures me that the proper...
Does anyone know of an acceptable test for evaluating resin properties of a laminate after a cure? I was thinking of probably using ASTM D2344 (short beam, interlaminar shear) but my problem is that the laminate has a cured ply thickness of only .025 inches. This is well below the parameters...
A question for any FEMAP users. My FEM will require a material card for a film adhesive. The properties that I have for the film adhesive are shear modulus, strain at failure and maximum shear stress. What would be the best material card to use for this material?
I would call TECs but it has...
First of all, thanks to you both for your replies. Porosity was what I expected as I have seen things like this happen when beryllium copper was plated with gold without an intermediate plating of something such as nickel. Ed - there was no special operation to smooth or seal the Ultem before...
We made a part from ULTEM 9085 using additive manufacturing and then electroplated it with copper. It didn't take long for the darn thing to start corroding. Does anybody know what the heck is happening?