A new mechanical device was developed to apply internal pressure loading to a cylindrical structure in order to determine its failure strength and failure mode under pressure loading. The device can be used for a uniaxial testing machine to apply internal pressure to a cylindrical structure. As a result, the developed device does not require any fluid to generate internal pressure loading. The device consists of two truncated conical shape of rams and eight pieces of the identical shape of wedges. The effectiveness of the device was assessed using both detailed finite element analyses of metallic cylinders as well as the analytical analysis. Then, a set of experimental tests were undertaken for aluminum alloy cylinders in order to evaluate experimental failure strength against the numerical and analytical results. Finally, composite cylinders made of glass-fiber or carbon-fiber woven fabrics were tested using the device, and the experimental results were compared to the predicted results using a multiscale analysis model. Those results agreed well with each other.