Study on damage failure for a new double-triangular truss core sandwich structure.

Area of Science:

• Materials Science
• Mechanical Engineering
• Composite Materials

Background:

• Traditional sandwich structures face challenges with low bonding strength between face and core materials.
• Thermoplastic composites like carbon fiber reinforced polyether ether ketone (CF/PEEK) offer potential for improved material interfaces.

Purpose of the Study:

• To propose and investigate a new double triangular truss core sandwich structure with reinforced frames.
• To evaluate the bending performance and failure mechanisms of this novel structure under three-point bending loads.
• To compare its performance against conventional honeycomb and V-shaped core structures.

Main Methods:

• Theoretical analysis to establish prediction equations for bending stiffness and strength.
• Finite element modeling using Abaqus to simulate three-point bending and predict failure modes.
• Experimental validation by comparing theoretical and numerical results.

Main Results:

• Theoretical and finite element models show good agreement, with an average error of 7.94% in deflection curves.
• The proposed double triangular truss core structure demonstrates superior bending resistance and ultimate load capacity compared to honeycomb and V-shaped structures.
• Identified failure modes include panel crumpling, reinforcement fracture, and core rod buckling/fracture.

Conclusions:

• The new double triangular truss core sandwich structure effectively enhances bonding strength and bending performance.
• The developed theoretical model accurately predicts the structural response, validating the design.
• This structure presents a promising alternative for applications requiring high bending resistance in composite materials.