This paper describes mechanical tests of aluminum profiles strengthened and stiffened with unidirectional laminates made of carbon fiber reinforced polymers (CFRP). Both lightweight materials, aluminum and CFRP, have advantages and disadvantages. Advantages of CFRP: high modulus of elasticity, high strength, excellent fatigue behavior and very light. Advantages of aluminum: easy to mill, cut, drill holes, form, weld, light and relatively inexpensive. Both are corrosion resistant on their own and easy to bond. Disadvantages of CFRP: difficult to mill, cut, drill, form, weld and expensive. Disadvantage of aluminum: relative low modulus of elasticity, only moderate fatigue behavior. With the combination of CFRP and aluminum, the advantages of both materials can be combined and the disadvantages neglected.

Based on good experimental test results, an aluminum semi-trailer with a length of 13.4 meters was stiffened with high-modulus CFRP strips. The vehicle was in use for 20 years without any problems.

When creating the bond between CFRP laminates and aluminum profiles, care must be taken to ensure that an insulating layer is installed between the bond partners to prevent galvanic corrosion. At Empa, tests running over a period of thirty years on a CFRP/Al composite beam have proven that galvanic corrosion can be prevented this way.

Key Words – galvanic corrosion, semi-trailer.