Abstract: A material test system capable of applying multiple force load components simultaneously includes a first actuator connected in parallel with a spring element. The first actuator and the spring element in turn are connected in series with the test specimen and a second actuator. The spring element is substantially rigid in order to transfer the force load from the second actuator to the test specimen yet substantially compliant in order to allow transfer of the force load from the first actuator to the test specimen.

Abstract: A gas convection assembly is disclosed for maintaining a desired temperature gradient on a test portion of a test specimen. The assembly includes a housing having a chamber defined by bounding walls. The chamber is accessible through apertures in the housing. The housing is positioned relative to the test specimen such that the apertures are substantially aligned along a longitudinal axis of the test specimen with the test portion located in the chamber and end portions of the test specimen that extend out the apertures. A fan is provided to force gas into the chamber to heat or cool the test portion.

Abstract: A specimen grip for a test specimen that has an actuator for operating the grip remotely mounted and coupled to the grip through a tubular housing which provides for temperature isolation between the grip and the actuator. The grip is specifically adapted to be used in environmental chambers where the grip must operate in either high or low temperatures which can have an effect on the hydraulic actuator used in the grip and connected devices, such as load sensors. By maintaining the actuator on the exterior of the environmental chamber by having a pair of modules that are connected by a sectional connector, a grip can be installed through small ports in the environmental chamber. Once installed, the assembly permits viable operation because the actuator is temperature isolated from the chamber.

Abstract: A tensile test grip for holding a specimen has a pullrod that is mounted in an annular bore, and carries a piston head that fits within a piston chamber, and both the pullrod and piston head are sealed on their outer surfaces with respect to the body forming the piston chamber, to form an enclosed chamber in which hydraulic fluid can be provided to permit swiveling alignment of the pullrod and the piston head relative to the housing that is a function of the direction of loading between the pullrod and the housing. The seal on the pullrod and the seal on the piston head with respect to the respective surfaces on which they seal is on a very short part spherical land to permit the pullrod and piston head to shift with respect to the housing and provide self alignment. The pullrod and piston can swivel freely for a limited amount to provide alignment during tensile loads.