Sandwich Composite Shell under Pressure

Subject a simply-supported sandwich shell (two outer facing sheets and an inner core) to a uniform normal pressure of 100 psi. Determine the central transverse displacement (top surface), SX and SY stresses at center of the top sheet, and TXY stress at the quarter point of the top sheet.

File Name

Open drive letter:\Users\Public\Public Documents\SOLIDWORKS\SOLIDWORKS version\samples\Simulation Examples\Verification\NAFEMS_IC31.SLDPRT.

Study Type

Static

Mesh Type

Shell mesh

Shell Parameters

Symmetric 3-layered sandwich composite with two outer face sheets and a middle core. Face sheets are 0.028 inches thick and core is 0.750 inches thick.

Material Properties

Linear elastic orthotropic with the following properties for:

Face Sheets
  • Elastic moduli: Ex = 10 x 106 psi, Ey = 4 x 106 psi

  • Poisson's ratio: νxy = 0.3

  • Shear modulus. Gxy = 1.875 x 106 psi

Core
  • Elastic modulus. Ex ~0
  • Shear moduli. Gxz = 3 x 104 psi, Gyz = 1.2 x 104 psi
The x direction is along the material fiber direction, the y direction is along the transverse in-plane direction, and the z direction is out-of-plane. These directions are different from the global X, Y, and Z directions.

Modeling Hints

Due to symmetry, only a quarter of the sandwich shell is modeled.

Results

Component NAFEMS SOLIDWORKS Simulation
Deflection UZ at C (in) -0.123 -0.126
Stress SX at C (top face of third ply) in psi 34449 35590
Stress SY at C (top face of third ply) in psi 13350 13896
Stress TXY at E (top face of third ply) in psi -5067.5 -5262.1
UZ, SX, and SY are obtained at the annotated location in the model that reads C. TXY is obtained at center of the model.

Reference

NAFEMS, Publication R0031/2, "Composites Benchmarks", February 1995.