Experimental Investigation of Bending Behaviors and Fracture Mode of Helicoidally Laminated CFRP Box Beams

Key Points

• Examine the bending behavior and fracture modes of helicoidally laminated CFRP beams compared to orthogonal laminated beams.
• Conducted four-point bending tests on two types of CFRP box beams.
• Analyzed load-displacement relationships to observe bending behavior.
• Investigated the effects of orientation angle differences on strain and fracture patterns.
• Utilized X-ray CT imaging to identify internal fractures.
• Observed reduced load drop after maximum load for beams with smaller orientation angle differences.
• Confirmed gradual softening in bending behavior for helicoidally laminated beams.
• Identified distinctive zigzag fracture patterns in helicoidally laminated beams versus linear cracks in orthogonal beams.
• Detected internal stair-step fractures across layers using X-ray CT imaging.