Original Article
  • Analysis on Stitched Mode I Specimen Using Spring Elements
  • Jonathan Tapullima, Hyung Woo Sim, Jin Hwe Kweon, Jin Ho Choi
  • Research Center for Aircraft Parts Technology, School of Mechanical and Aerospace Engineering, Gyeongsang National University
  • Analysis on Stitched Mode I Specimen Using Spring Elements
  • Jonathan Tapullima, Hyung Woo Sim, Jin Hwe Kweon, Jin Ho Choi
Abstract
Several studies related to reinforce composites structures in the through thickness direction have been developed along the years. As follows, in this study a new reinforced process is proposed based on previous experimental results using a novel stitching process in T-joints and one-stitched specimens. It was established the need to perform more analysis under standard test methods to obtain a better understanding. FEM analysis were compared after performed mode I interlaminar fracture toughness test, using different stitching patterns to analyze the through thickness strength with reference laminates without stitching. The stitching patterns were defined in 2 × 2 and 3 × 3, where the upper and lower head of the non-continuous stitching process (I-Fiber) has proven to influence in a higher through thickness strength of the laminate. In order to design the numerical model, cohesive parameters were required to define the surface to surface bonding elements using the cohesive zone method (CZM) and simulate the crack opening behavior from the double cantilever beam (DCB) test.

Several studies related to reinforce composites structures in the through thickness direction have been developed along the years. As follows, in this study a new reinforced process is proposed based on previous experimental results using a novel stitching process in T-joints and one-stitched specimens. It was established the need to perform more analysis under standard test methods to obtain a better understanding. FEM analysis were compared after performed mode I interlaminar fracture toughness test, using different stitching patterns to analyze the through thickness strength with reference laminates without stitching. The stitching patterns were defined in 2 × 2 and 3 × 3, where the upper and lower head of the non-continuous stitching process (I-Fiber) has proven to influence in a higher through thickness strength of the laminate. In order to design the numerical model, cohesive parameters were required to define the surface to surface bonding elements using the cohesive zone method (CZM) and simulate the crack opening behavior from the double cantilever beam (DCB) test.

Keywords: I-fiber, Stitching, DCB (Double Cantilever Beam), CZM (Cohesive Zone Method), Interlaminar Fracture Toughness

Keywords: I-fiber, Stitching, DCB (Double Cantilever Beam), CZM (Cohesive Zone Method), Interlaminar Fracture Toughness

This Article

  • 2019; 32(2): 102-107

    Published on Apr 30, 2019

Correspondence to

  • E-mail: