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Pages
- Title
- Compression failure of sandwich specimens with and without face/core debonds.
- Creator
- Vadakkeveedu, Vinod P., Florida Atlantic University, Carlsson, Leif A., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The objective of this thesis is to report on an experimental study on the compressive behavior of foam cored sandwich composite specimens with and without face/core debond. A test fixture was designed which enables a precisely machined sandwich specimen instrumented with back-to-back strain gages to be loaded in edgewise compression. Tests were conducted on specimens without implanted face/core interface debonds over a range of core densities and gage lengths. The experimentally determined...
Show moreThe objective of this thesis is to report on an experimental study on the compressive behavior of foam cored sandwich composite specimens with and without face/core debond. A test fixture was designed which enables a precisely machined sandwich specimen instrumented with back-to-back strain gages to be loaded in edgewise compression. Tests were conducted on specimens without implanted face/core interface debonds over a range of core densities and gage lengths. The experimentally determined compression strengths and failure modes were compared to closed-form predictions and finite element analysis. Specimens with an implanted through-the-width face/core debond were also tested and mechanism of failure was analyzed using finite element analysis. Good agreement between collapse loads predicted using geometrically nonlinear analysis and experimentally measured strengths was observed.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13047
- Subject Headings
- Sandwich construction, Strains and stresses, Structural analysis (Engineering)
- Format
- Document (PDF)
- Title
- Investigation of debonding and crack kinking in foam core sandwich beams.
- Creator
- Prasad, Srinivas., Florida Atlantic University, Carlsson, Leif A., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Debond failures in structural sandwich may lead to severe reductions in load-bearing capability of the structure because of impartial transfer of shear and tensile forces between facing and core due to the lack of interfacial bonding. Analysis of interfacial bonding in sandwich specimens subjected to transverse tensile and shear forces is presented. Stress intensity factors computed based on the near-tip displacement field are related to experimental crack growth observation on the sandwich...
Show moreDebond failures in structural sandwich may lead to severe reductions in load-bearing capability of the structure because of impartial transfer of shear and tensile forces between facing and core due to the lack of interfacial bonding. Analysis of interfacial bonding in sandwich specimens subjected to transverse tensile and shear forces is presented. Stress intensity factors computed based on the near-tip displacement field are related to experimental crack growth observation on the sandwich beams with aluminum skins on a wide range of PVC foam cores. Experimentally it was found that the crack tends to grow at the interface between the bondline and core as opposed to skin/bondline interface. In shear dominated fields, a pre-existing flow tended to deflect into the core rather than grow along the interface. The tendency for kinking and the direction of the kink is examined experimentally and analyzed using the finite element method.
Show less - Date Issued
- 1993
- PURL
- http://purl.flvc.org/fcla/dt/14861
- Subject Headings
- Finite element method, Sandwich construction, Diffusion bonding (Metals), Fracture mechanics
- Format
- Document (PDF)
- Title
- INFLUENCE OF DEFORMATION CONSTRAINTS OF HONEYCOMB CORE CELLS ON THE BENDING STIFFNESS OF SINGLE-FACE SANDWICH.
- Creator
- Ayanoglu, Mustafa Oguzhan, Carlsson, Leif A., Du, E, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
- Abstract/Description
-
This research focuses on deformation constraints of honeycomb core cells in a sandwich imposed by bonds to the face sheets. Specifically, the influence of one-sided core constraints on the bending stiffness of a single-face honeycomb core sandwich is examined. To characterize the unconstrained in-plane compressive response of honeycomb core, a range of honeycomb cores was experimentally examined. Cores with a thin cell wall displayed extensive bending deformation of inclined cell walls while...
Show moreThis research focuses on deformation constraints of honeycomb core cells in a sandwich imposed by bonds to the face sheets. Specifically, the influence of one-sided core constraints on the bending stiffness of a single-face honeycomb core sandwich is examined. To characterize the unconstrained in-plane compressive response of honeycomb core, a range of honeycomb cores was experimentally examined. Cores with a thin cell wall displayed extensive bending deformation of inclined cell walls while cores with thicker walls failed by a shear-type instability of the cells indicated by tilting of vertical cell wall segments. The modulus and compressive strength of the core were compared to the predictions from unit cell models. The results show that geometrical imperfections such as deviation from the intended cell wall angle cause in-plane anisotropy and have strong influence on modulus and strength of the core. Modulus and strength were in reasonable agreement with predictions from unit cell models for cell wall modulus and strength between 5-12 GPa and 72-171 MPa for the set of cores examined.
Show less - Date Issued
- 2024
- PURL
- http://purl.flvc.org/fau/fd/FA00014438
- Subject Headings
- Honeycomb structures, Materials--Compression testing, Sandwich construction
- Format
- Document (PDF)
