Stress Analysis of Spinning Disks

 As a first order analysis to determine whether or not a plastic disk would shatter spinning at high rotational speeds, a quick rotational stress calculation was done. From The Engineering Toolbox, the stress can be calculated as shown in the two images below. ABS plastic was chosen as the material. 

Method 1
Item	Value	Units	Notes
RPM	5000	rev/min	From Zach's Design
Radius	0.0458	m	From Zach's Design
Density	1060	kg/m^3	Abs Plastic
Stress	202751.49	Pa
	29.41	psi
Ult.Tensile Strength	5500	psi	Source
FOS	187

In Google Sheets the stress was found to be ~29 psi with a 0.0458 m radius disk spinning at 5000 RPM. 

The second method is from a forum where the stress was calculated as shown.  

Method 2
Item	Value	Units	Notes
RPM	5000	rev/min	From Zach's Design
Radius	0.0458	m	From Zach's Design
Density	1060	kg/m^3	Abs Plastic
Poisson's	0.35		Source
Max Stress	254706.56	Pa
	36.94	psi

This method produced a maximum stress of 37 psi, closely matching the previous result. The main difference with this method was ABS plastics' Poisson's ratio was taken into account.