Example 5.3: Angle-ply symmetric laminate .

Solution: The coordinates for this laminate are shown in Figure 5.10 (a). For this laminate .  is the same as in Example 5.1. Now,  for  and  is calculated below.

Thus,

Since the laminate is symmetric, .

Putting the values of  and , we get

Note: In this example, the middle two  layers of 1 mm thickness can be treated as one layer of layer with 2 mm thickness. The A, B and D matrices should be the same. The readers are suggested to check this.

Example 5.4: Angle-ply anti-symmetric laminate

Solution: The coordinates for this laminate is shown in Figure 5.10(b). Here, .   is the same as in Example 5.1.  for  and  are the same as in Example 5.3.

 is the same as in Example 5.3.

This gives,

Now we calculate matrix D as

Putting  and  gives