Comparison of Failure for Thin-Walled Composite Columns.

Area of Science:

• Materials Science
• Mechanical Engineering
• Structural Analysis

Background:

• Thin-walled composite structures are crucial in aerospace and automotive industries.
• Understanding failure mechanisms in composite materials under axial compression is vital for design optimization.
• Existing research often focuses on single cross-sections, necessitating comparative studies.

Purpose of the Study:

• To comparatively analyze the failure phenomenon of thin-walled composite structures with top-hat and channel cross-sections.
• To validate advanced numerical models against experimental data for composite material failure.
• To investigate damage initiation, delamination, and load-carrying capacity loss.

Main Methods:

• Experimental testing of carbon fiber reinforced polymer (CFRP) composite columns under axial compression using a universal testing machine (UTM) and acoustic emission (AE) monitoring.
• Numerical simulations employing the finite element method (FEM) with progressive failure analysis (PFA) and cohesive zone models (CZM).
• Autoclave manufacturing technique for high-quality composite specimens.

Main Results:

• High qualitative and quantitative agreement between experimental and numerical failure predictions.
• Identification of damage initiation, delamination, and loss of load-carrying capacity as key failure modes.
• Dominant failure modes observed at the end sections of composite columns, with delamination prevalent on outer flanges.

Conclusions:

• The study successfully validated advanced numerical models for predicting composite failure in different cross-sections.
• The findings provide critical insights into the stability and failure behavior of thin-walled composite structures.
• The research highlights the importance of cross-sectional geometry in the failure mechanisms of CFRP components.