Mechanical and Microstructural Characterization of Trapezoidal Corrugated-Core Al Sandwich Panels Under Quasi-Static...

Area of Science:

• Materials Science
• Mechanical Engineering
• Structural Analysis

Background:

• Sandwich panels with trapezoidal cores are recognized for their low weight, high specific stiffness, and energy absorption.
• Understanding the influence of core geometry on mechanical performance is crucial for optimizing their application.

Purpose of the Study:

• To analyze the microstructural and mechanical behavior of trapezoidal cored sandwich panels with varying core heights.
• To evaluate the impact of core height on stress-strain response, peak stress, and energy absorbed density (EAD).

Main Methods:

• Microstructural analyses including optical microscopy, Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS), and X-ray Diffraction (XRD).
• Quasi-static compression tests to obtain stress-strain curves and quantify mechanical properties.
• Analysis of four configurations with different core heights (P1 to P4).

Main Results:

• Stress-strain curves exhibited distinct stages: linear, peak, plateau, and densification.
• Peak stresses ranged from 0.5 MPa (thickest core, P1) to 6.2 MPa (thinnest core, P4).
• Energy absorbed density (EAD) increased with strain, reaching ≈1.113 J/cm³ at 50% strain for the thinnest core.
• Microstructural analysis revealed micro-porosity and Fe/Mn-rich phases in the AA 3000 aluminum alloy.
• Increasing core height led to earlier instabilities and reduced peak stress; the thinnest core showed superior stiffness and peak loads.

Conclusions:

• Core height significantly influences the mechanical performance of trapezoidal cored sandwich panels.
• Thinner cores offer higher stiffness and peak load capacity, suitable for applications requiring progressive strain.
• The findings support the use of trapezoidal corrugation in lightweight structures demanding controlled energy absorption.