U.S. flag An official website of the United States government.
Official websites use .gov

A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS

A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

i

Point Cloud Failure Criterion for Impact Modeling of Composite Structures

File Language:
English


Select the Download button to view the document
Please click the download button to view the document.

Details

  • Creators:
  • Corporate Creators:
  • Corporate Contributors:
  • Subject/TRT Terms:
  • Publication/ Report Number:
  • DOI:
  • Resource Type:
  • Geographical Coverage:
  • Edition:
    Technical Thesis
  • Contracting Officer:
  • Corporate Publisher:
  • Abstract:
    An orthotropic elasto-plastic damage material model (OEPDMM) suitable for impact analysis of composite materials has been developed through a joint research project funded by the Federal Aviation Administration (FAA) and the National Aeronautics and Space Administration (NASA). The developed material model has been implemented into LS-DYNA®, a commercial finite element program. The material model is comprised of deformation, damage and failure sub-models. The deformation sub-model captures rate- and temperature-dependent elastic and inelastic behavior through a viscoelastic-plastic formulation. The damage sub-model accounts for reductions in elastic stiffness, while the failure sub-model predicts complete loss of load-carrying capacity, leading to element erosion. The primary objective of this dissertation is to improve the failure prediction sub-model. Traditional failure theories using analytical expressions to predict failure either in the composite or its constituents have not proven to be reliable. To overcome the predictability conundrum, a multi-scale modeling scheme based on a combination of virtual and laboratory testing is used to generate the failure surface as point cloud data points in the stress/strain space. At the microscale, the constituent components of the composite are used in modeling a representative volume element (RVE) that is subjected to multi-axial state of stress until the first failure in the RVE is detected. These discrete points are used in the developed Point Cloud Failure Criterion (PCFC). The secondary objectives of the dissertation are to enhance OEPDMM capabilities - (a) develop a new deformation sub-model, the Simplified Material Model that can be used for modeling materials exhibiting little or no elasto-plastic behavior, and (b) develop a framework for obtaining traction-separation law using inverse analysis for modeling delamination in laminated composites. Five validation tests were conducted to assess the accuracy, efficiency and versatility of available capabilities of OEPDMM. The findings from this research establish a robust foundation for future advancements in constitutive modeling of composite materials, with ongoing efforts directed toward extending PCFC to thick-shell and solid finite elements, incorporating rate and temperature-dependent failure surface, and incorporating mesh regularization techniques to further improve computational efficiency and accuracy in high-fidelity finite element simulations.
  • Format:
  • Funding:
  • Collection(s):
  • Main Document Checksum:
    urn:sha-512:559e48b7d446045b595dbcf63fcc3b290f58c9abd55957ad5e0296a6497b7c4be6d00dc12c6d38e3c64e803f065dc69846198add73a360d404ecef1a6f6c997d
  • Download URL:
  • File Type:
    Filetype[PDF - 10.27 MB ]
File Language:
English
ON THIS PAGE

ROSA P serves as an archival repository of USDOT-published products including scientific findings, journal articles, guidelines, recommendations, or other information authored or co-authored by USDOT or funded partners. As a repository, ROSA P retains documents in their original published format to ensure public access to scientific information.