Hydraulic Sequential Fatigue & Pull Tester

The Hydraulic Pull / Fatigue Tester is a dual-purpose machine capable of either function, but not both concurrently.  Any number of single-cylinder stations are available even though the one shown is a two-station version.  This system also includes a separate, floor standing, P.C. based Control & Data Acquisition system, and a separate hydraulic power source.

Each station is free standing and can be attached to either the customer's existing bedplate or a bedplate can be provided with the tester.  Each hydraulic cylinder has 24 inches (610mm) of stroke, double rods, a fatigue rated load cell and an internal displacement transducer (which is independent of rotation).  Each cylinder is mounted in a balanced (at mid-stroke) 2-way gimbal arrangement allowing for either free motion in both the vertical and lateral axis, or locked positioning in both axis.  The centerlines of these gimbal mounts are positioned ahead of the vertical face to provide an offset clearance for true vertical pull and fatigue testing.   This entire cylinder mounting mechanism is then fully counterbalanced, so it can be easily raised and lowered by hand.

Cylinder capacities can be up to 10K pounds per station, but it is advised to not request them much larger than is necessary. This improves test accuracy and dynamic response for the majority of specification requirements.  A dedicated servo-hydraulic valve and controller, for maximum load accuracy and response speed, operate each cylinder.

The P.C. based Control and Data Acquisition System is housed in a separate, floor standing console.  The software is custom programmed by Schap Specialty Machine, Inc. in Visual Basic, and operates in a standard Windows environment.  Loading profiles, for either pull or fatigue tests, can be individually programmed for each cylinder.  Data acquisition of load and position is automatically plotted for each cylinder with a wide selection of user and display options.   The final graphical result can then be printed on the plain paper color ink jet printer, which is housed within the console.  The test data can be saved or downloaded onto any other suitable P.C. type format.

Generally, this destructive test system is rather simple to both set-up and operate.  Technicians that are P.C. literate will have no trouble learning how to operate the software quickly

choose image to enlarge