Influence of wind turbine blade recyclates on the CoR and failure characteristics of composite panels for intermodal containers and trucks

Traditional sandwich composite panels consist of stiff facesheets that support bending loads and a core that bears shearing load. In this study, the core and facesheet were assembled in a single process to eliminate the possibility of delamination between the layers, and make the structure unitary in its construction. The drop tower impact test was conducted in accordance to ASTM standard D7136 to evaluate the impact strength of the panels while taking into consideration the impact velocity and the coefficient of restitution. The impact velocities used were 1 m/s and 4.6 m/s denoted as <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>V</mml:mi> <mml:mrow> <mml:mn>1</mml:mn> <mml:mfrac> <mml:mi>m</mml:mi> <mml:mi>s</mml:mi> </mml:mfrac> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>V</mml:mi> <mml:mrow> <mml:mn>4.6</mml:mn> <mml:mfrac> <mml:mi>m</mml:mi> <mml:mi>s</mml:mi> </mml:mfrac> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> respectively. A Phased Array Ultrasonic Testing (PAUT) inspection was conducted to evaluate damage extent in the high velocity samples. At <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>V</mml:mi> <mml:mrow> <mml:mn>4.6</mml:mn> <mml:mfrac> <mml:mi>m</mml:mi> <mml:mi>s</mml:mi> </mml:mfrac> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> , the CoR ranged between 0.05 and 0.363, suggesting some amount of elastic collision. The displayed Energy Loss Percentage (ELP) was more than 85%, suggesting that the specimen experienced total perforation. There were mainly dents on the front side and bulges on the opposite sides of the specimens tested at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi mathvariant="italic">V</mml:mi> <mml:mrow> <mml:mn>1</mml:mn> <mml:mfrac> <mml:mi mathvariant="italic">m</mml:mi> <mml:mi mathvariant="italic">s</mml:mi> </mml:mfrac> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> while at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>V</mml:mi> <mml:mrow> <mml:mn>4.6</mml:mn> <mml:mfrac> <mml:mi>m</mml:mi> <mml:mi>s</mml:mi> </mml:mfrac> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> , the specimens experienced considerable damage including perforation. Ultrasound (UT) inspection of the damaged specimens did not show delamination. Avoiding dislocation of structural members when manufacturing composite panels for intermodal containers and truck beds was achieved.