Thick where the load goes in
Load enters a part at a few points (bolts, attachments) and spreads out, so plies are added locally where it is crowded and tapered away where it is not; AddPly's spar section reads about 4.5 mm at the root and 2.1 mm towards the tip.
Predict · at 0:51 in the video
Where does a bolted bracket need extra plies?
Around the bolt holes, and along the paths the load takes into the part. AddPly's wing spar shows the same idea. Cut a section along it: thick at the root, where a spar is attached, stepping down towards the tip.
This course is our own. These books go deeper.
- Basic Mechanics of Laminated Composite Plates, A. T. Nettles, NASA Reference Publication 1351, 1994
- Mechanics of Composite Materials, R. M. Jones, Taylor & Francis, 2nd ed., 1999
- Engineering Mechanics of Composite Materials, I. M. Daniel & O. Ishai, Oxford University Press, 2nd ed., 2006
- Design and Analysis of Composite Structures, C. Kassapoglou, Wiley, 2nd ed., 2013
- Composite Materials Handbook (CMH-17), Volume 3, Rev. G, CMH-17, SAE International, 2012
The course designs in AddPly, our browser app for laminate design: regions, ply stacks with live stacking-rule checks, thickness, mass and the ply book, plus hosted drape studies and linear FEA with maximum-stress screening, within their stated limits. The lessons teach the theory behind those on our own simulations, so you can judge the results. AddPly needs an Addcomposites sign-in.
Simulations in this lesson are our own. Ply data come from the datasheet or textbook named on screen; where a number rests on an assumption, the video says so.
