Contact Force vs Contact Pressure

Discussion created by 1-CQFVQE on Mar 12, 2009
Latest reply on Mar 16, 2009 by Jeff Gillis
Hi - I have a basic question on the contact pressure plots using COSMOSWorks.

I am performing a seat tightness study in a pressure relief valve that has internal pressure acting on two components in contact. This pressure is biased against a spring force. My objective is to find the max internal pressure achievable without leakage. I study the contact pressure at the seat as the metric that determines seat tightness. If contact pressure exceeds internal pressure, the valve seals tight.

After performing a no-penetration contact analysis, when I analyze the results, I look at the contact pressure in 2 ways

1. I get the contact force value and divide it by the average contact area (which is derived from the contact pressure plot). The contact force is equal and opposite on the contacting faces.

2. I get the average contact pressure value from the source or the target face (whichever is minimum, mostly the target face).

These two methods do not agree with each other, and in some cases vastly different. Which one is the more accurate method? Or is there a better method to do the analysis. I have had success from the first method (proven on the field).

Thank you