Stress Concentration in Pressure Cylinder

There are ever increasing demands in industry to design products that are lighter, cheaper and have optimum performance.  Many hydraulic valve blocks and cylinders have intersecting pressure vessels which introduce stress concentration factors (Kt Factors).  The stress concentration factors are often reduced through addition of extra weight or a less acute angle of intersection which consequently affect the overall weight and performance.

This project investigated stress concentration factors induced by intersecting bores within pressure cylinders. 

The investigation included theoretical hand calculations, test equipment operational procedures, and  the design of experimental techniques necessary to overcome problems encountered with the initial testing of specimens.  It  used the latest software approaches such as finite element analysis and included pressure impulse fatigue testing on sampled test blocks.

The investigation showed how varying angles of intersecting pressure bores affected stress concentration and thus fatigue life of a valve block and validated the analysis with an impulse pressure fatigue test on the design for experiment test specimen.

The investigation quantified the affect that changing the angle of an intersecting bore has on the stress concentration.  This could potentially reduce manufacturing costs, reduce weight and decrease lead time.

A pressure cylinder