Shear angle and locking
A weave can only shear so far: at its locking angle the yarns jam and it wrinkles (measured per fabric). On our dome drape, with an illustrative 40° locking angle, 2% of the dome goes past it starting from the top; start 30° off the top and the worst shear rises from 42° to 62°, with 10% past 40°.
Predict · at 0:46 in the video
Where on a dome is the shear largest?
Away from the two starting fibres: out on the diagonals, near the rim. Now start thirty degrees off the top. The map moves.
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. It does not do strength, failure or draping; where a lesson covers those, the simulation is our own.
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.