For the following calculations we will only consider plates of uniform thickness and with a uniformly distributed load over the entire surface. This will help us define minimum thickness’ for components such as pressure vessels or piston housings.

Simply Supported

The maximum bending stress of a simply supported plate can be calculated by:

Stress at centre of plate

a=plate length, b=plate width

a/b	1.0	1.2	1.4	1.6	1.8	2.0	3.0	4.0	5.0
	0.2874	0.3762	0.4530	0.5172	0.5688	0.6102	0.7134	0.7410	0.7476	0.7500

For values of a/b not given in table, round down to the next respective value i.e. assuming maximum stress values for conservatism.

Fixed Support

For a plate that is fixed supported i.e. built into the structure, the maximum bending stress (at the centre of longer edges) can be calculated by:

Max stress at centre of long edge

Stress at centre of plate

a/b	1.0	1.2	1.4	1.6	1.8	2.0
	0.3078	0.3834	0.4356	0.4680	0.4872	0.4974	0.5000
	0.1386	0.1794	0.2094	0.2286	0.2406	0.2472	0.2500

For values of a/b not given in table, round down to the next respective value i.e. assuming maximum stress values for conservatism.