Patent ID: 8978480
Filing Date: 2015-03-17
Classification: G01N

Abstract:
1. A materials testing machine for six degrees of freedom multiaxial testing of specimens held between a fixed base and a movable base, the machine comprising: a fixed base; and a movable base, the movable base being connected to the fixed base by a hexapod arrangement of six linearly extendable actuator linkages, a first end of each actuator linkage being attached to the movable base, a second end of each actuator linkage being attached to the fixed base; each of the actuator linkages including a hydraulic cylinder and piston, a digitally controlled electro-hydraulic servo-valve for actuating the hydraulic cylinder in response to a digital command string, a load cell in line between the piston and a universal joint attached to the movable base, a linear displacement transducer for measuring an extension of the piston, and a magneto-resistive position transducer for measuring a position of the piston, wherein in operation, operation of each of the servo-valves extends each hydraulic cylinder a predetermined amount to effect a desired motion of the material specimen.