Resonance of laminated parts causes fatigue delamination

Fatigue delamination appears in laminated structural parts under long-term vibration conditions. The interlayer separation phenomenon gradually expands after the product is subjected to force or environmental action, seriously affecting structural integrity.

(1) Stress distribution aspect: At the resonance frequency, the cyclic shear stress on the interlayer exceeds the interlaminar fatigue limit, Internal stress concentration causes the product to crack or deform during subsequent use. (2) Interface aspect: Insufficient interlayer bonding force, inadequate resin impregnation, or the resin has gelled and lost tack. (3) Process aspect: Interlayer contamination or insufficient temperature/pressure causes the interface to not fully fuse. (4) Material aspect: Poor compatibility between the resin and the reinforcement material surface.

(1) Implementation measure: Perform modal analysis during design to avoid the structural resonance frequency zone, Develop a specific operation plan based on actual production conditions, and verify the implementation effect. (2) Formulation optimization: Add interlayer toughening particles or intercalation to improve interlaminar fracture toughness., Determine the optimal addition amount through small-batch tests, and verify the effect on the overall performance of the product. (3) Process control: Ensure full impregnation and interlayer bonding, and complete lay-up within the pot life of the resin. (4) Operation specification: Keep the interlayers clean and free of contamination, and control the lay-up operation environment. (5) Preventive measure: Establish interlaminar bond strength inspection standards, regularly sample interlaminar shear strength, and monitor process parameter stability.

The essence of the interlayer separation problem is insufficient interfacial bonding force; it needs to be systematically improved from three aspects: impregnation quality, interlayer cleaning, and process parameters.