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Micromechanics of the through-thickness deformation of paperboard

IP.com Disclosure Number: IPCOM000128106D
Original Publication Date: 1999-Dec-31
Included in the Prior Art Database: 2005-Sep-14
Document File: 7 page(s) / 21K

Publishing Venue

Software Patent Institute

Related People

Smith, Carmen Alexis: AUTHOR [+3]

Related Documents

http://theses.mit.edu:80/Dienst/UI/2.0/Describe/0018.mit.theses/1999-140: URL

Abstract

An experimental investigation of the behavior of paperboard has been performed, focusing on the identification of the mechanisms of through-thickness deformation. Experiments have been conducted at the microscopic and macroscopic levels, the difference between the two being the length scale. Experiments at the microscopic level were performed in a scanning electron microscope, allowing concurrent viewing of the deformation as it took place with acquisition of load vs. displacement data. The experiments at the macroscopic level confirm the mechanisms observed at the microscopic level and provide more accurate, continuum-level stress-strain data.

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 This record is the front matter from a document that appears on a server at MIT and is used through permission from MIT. See http://theses.mit.edu:80/Dienst/UI/2.0/Describe/0018.mit.theses/1999-140 for copyright details and for the full document in image form.

Micromechanics of the Through-thickness Deformation of Paperboard

by

Carmen Alexis Smith
Bachelor of Science in Mechanical Engineering, Massachusetts Institute of Technology (1995) Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in MECHANICAL ENGINEERING

at the Massachusetts Institute of Technology

February 1999
SIGNATURE OF author: [[signature omitted]]

Department of Mechanical Engineering

January 15 1999

CERTIFIED BY: [[SIGNATURE OMITTED]]

Mary C. Boyce
Associate Professor Thesis Supervisor
David M. Parks
Professor Thesis Supervisor
ACCEPTED BY: [[SIGNATURE OMITTED]] Ain A. Sonin

Chairman, Department Committee on Graduate Students

ARCHIVES MASSACHUSETTS INSTITUTE OF TECHNOLOGY LIBRARIES JUL 12 1999

Massachusetts Institute of Technology Page 1 Dec 31, 1999

Page 2 of 7

Micromechanics of the through-thickness deformation of paperboard

[2]

Micromechanics of the Through-thickness Deformation of Paperboard

By Carmen Alexis Smith

Submitted to the Department of Mechanical Engineering on January 15, 1999, in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN MECHANICAL ENGINEERING

Abstract

An experimental investigation of the behavior of paperboard has been performed, focusing on the identification of the mechanisms of through-thickness deformation. Experiments have been conducted at the microscopic and macroscopic levels, the difference between the two being the length scale. Experiments at the microscopic level were performed in a scanning electron microscope, allowing concurrent viewing of the deformation as it took place with acquisition of load vs. displacement data. The experiments at the macroscopic level confirm the mechanisms observed at the microscopic level and provide more accurate, continuum-level stress-strain data.

The motivation for the investigation is the modeling of the creasing process, in which a sheet of paperboard is punched and folded along a narrow line to create a corner for packaging. Creasing experiments indicate that out-of-plane shear damage during punching and normal delamination during folding govern the quality of the resulting crease. Experiments in out-of- plane tension, compression, and simple shear have been performed to investigate the behavior of paperboard under these simple loading conditions.

The results show that normal and tangential delamination at the interfaces between layers is of extreme importance in the behavior of paperboard in tension and shear. Damage in the form of microcracks occurs almost from the onset of strain and culminates in large-scale delamination coincident with a large decrease in the strength of the material. In compression, the behavior is mostly...