The reinforcement of hollow 3D-printed aluminum alloy structures with CFRP (carbon fiber-reinforced polymer) is investigated for potential application in conformable and load-bearing lightweight pressure vessels. Positive locking load introduction methods are explored to mitigate stresses caused by differences in thermal expansion coefficients between the two materials. This is of particular interest in cryogenic hydrogen storage, where adhesive bonding may result in high interface stresses due to temperature changes. To address this, three different positive locking configurations for fiber anchoring and load introduction are explored. These are used to reinforce a hollow 3D-printed aluminum specimen, representing a tension reinforcement strut inside a pressure vessel. After an initial assessment of the potential advantages of aluminum-CFRP reinforcement, the configurations are proposed and conceptually analyzed. Specimens for each concept are then fabricated and tested under both static and cyclic loading to evaluate their behavior under both loading conditions. Finally, conclusions are drawn, and recommendations for further development of the reinforcements are presented.