Two adjustable compliant mechanism load deflection test benches are presented in this study. Both test bench mechanisms enable testing the deflection of flexible links or mechanisms. The modularity of the designs provides to test various link forms such as fixed-fixed and pinned-pinned joints. The load deflection test benches consist of a linear actuator, an amplifier rod, a linear rail and a sliding car. The measurement setup is equipped with force and displacement sensors for the linear actuator, various clamps to attach the compliant member, and machine vision software to measure member deflection. A displacement-controlled loading using a linear actuator, rack-pinion attached to a motor, or step loading with a pulley can be applied as an input to the system.

There are several limitations involved in the design. First, the length of the test object should be kept between 5 cm to 30 cm. Second, a low cost linear actuator with a low extension velocity to obtain quasi static deflection curves of the compliant members is required. Finally, the design should also have the capability of providing various types of boundary conditions with interchangeable attachments. The force can be applied either parallel or perpendicular to the test object. Input load deflection is measured with the displacement sensor, and the resulting member displacement measured visually using machine vision software. This software synchronizes data from the displacement sensor and a calibrated camera image to automatically detect deflection using a pinhole camera model and known dimensions of the test apparatus.

The purpose of this study is to design and fabricate a load deflection test setup capable of testing flexible links and compliant mechanisms. Two different designs are proposed and explored in this study. The first design is the modification of a commercially available ECP Model 210 educational turnkey system favorably utilized in undergraduate level vibrations and control labs. By attaching the designed clamps on two carts, fixed-fixed and U shaped compliant link load deflection can be obtained. Four cases such as fixed-fixed buckling beam, U shaped beam buckling with one end sliding, already buckled beam loaded at its upper midpoint, and inverse U-shaped beam loaded at its apex to form deflected M beam (with design 2) are considered. In order to achieve buckled beam experiments in which the load is applied at the midpoint of the already buckled links, a new test bench consisting of a linear actuator, rigid links, rail and two sliding cars is designed.

This content is only available via PDF.
You do not currently have access to this content.