Testing Procedure for Fatigue Characterization of Steel-CFRP Hybrid Laminate Considering Material Dependent...

Area of Science:

• Materials Science
• Mechanical Engineering

Background:

• Hybrid laminates combine carbon fiber reinforced polymers (CFRP) and steel to leverage unique material properties.
• Gradual failure in hybrid laminates can alter mechanical characteristics, particularly under fatigue loading.
• Metal component failure in hybrid structures increases stress and self-heating in the CFRP, necessitating careful evaluation.

Purpose of the Study:

• To develop a reproducible testing procedure for characterizing the fatigue performance of CFRP-steel hybrid laminates.
• To investigate the influence of manufacturing-induced residual stresses on the load-bearing capacity of these hybrid materials.
• To establish a foundation for future research on residual stress effects in hybrid laminate performance.

Main Methods:

• Development of a specialized testing procedure involving multiple frequency, load increase, and constant amplitude tests.
• Implementation of finite element analysis (FEA) to simulate and understand manufacturing-induced residual stresses.
• Careful control of testing parameters to maintain a temperature increase below 4 K during fatigue evaluation.

Main Results:

• A novel testing procedure was successfully established for reproducible fatigue characterization of CFRP-steel hybrid laminates.
• FEA simulations provided insights into the impact of residual stresses on the load-bearing capacity of hybrid laminates.
• Fatigue performance was characterized without inducing significant self-heating (ΔT < 4 K) in the CFRP component.

Conclusions:

• The developed testing procedure enables reliable assessment of fatigue performance in CFRP-steel hybrid laminates.
• Manufacturing-induced residual stresses significantly influence the load-bearing capacity and overall performance of these hybrid materials.
• Accurate fatigue characterization requires consideration of both the testing methodology and internal residual stress states.