Fracture and toughening of soft elastic composite

dc.contributor.advisor Wei Hong
dc.contributor.author Feng, Xiangchao
dc.contributor.department Aerospace Engineering
dc.date 2018-08-11T18:16:59.000
dc.date.accessioned 2020-06-30T03:01:48Z
dc.date.available 2020-06-30T03:01:48Z
dc.date.copyright Fri Jan 01 00:00:00 UTC 2016
dc.date.embargo 2001-01-01
dc.date.issued 2016-01-01
dc.description.abstract <p>Characterized by their low modulus and high stretchability, soft composites have recently attracted great interest from researchers in related areas. The main objective of the present study is on the fracture property and toughening mechanism of soft composites. Two types of soft composites will be studied: soft elastic foam and the double-network (DN) composite. A theoretical/numerical study is carried out over soft elastic foams. By using the analogy between the cellular structure of foams and the network of rubbery polymers, a scaling law for the fracture energy is proposed for soft elastic foams. A phase-field model for the fracture processes in soft elastic structures is further developed to study the crack propagation in an elastic foam, and results have all achieved good agreement with the scaling law. Simulations have shown that an effective fracture energy one order of magnitude higher than the base material can be reached by using the soft foam structure. To further enhance the fracture and mechanical toughness, the second part of the thesis presents a combined experimental and theoretical study of the DN soft composite, which consists of stacked layers of fabric mesh and 3M VHB tapes. The composite exhibits a damage evolution process very similar to that in the well-known DN hydrogels. The testing results show that the strength and toughness of the DN composite is highly dependent on the composition, and in certain range, the DN composite exhibits much higher mechanical strength and toughness compared with the base materials. A 1D shear-lag model is developed to illustrate the damage-distribution toughening mechanism of the double network composite. The prediction of the model agrees well with the measured properties of the composite in various compositions. The DN composite may also be regarded as a macroscopic model of the DN gel for understanding its structure-property relation.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/etd/15149/
dc.identifier.articleid 6156
dc.identifier.contextkey 8928995
dc.identifier.doi https://doi.org/10.31274/etd-180810-4767
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath etd/15149
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/29333
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/etd/15149/0-crack_tolerant.wmv|||Fri Jan 14 20:36:33 UTC 2022
dc.source.bitstream archive/lib.dr.iastate.edu/etd/15149/Feng_iastate_0097M_15629.pdf|||Fri Jan 14 20:36:40 UTC 2022
dc.subject.disciplines Aerospace Engineering
dc.subject.keywords Aerospace Engineering
dc.subject.keywords double network composite
dc.subject.keywords fabric mesh
dc.subject.keywords soft elastic foam
dc.subject.keywords VHB tape
dc.supplemental.bitstream crack_tolerant.wmv
dc.title Fracture and toughening of soft elastic composite
dc.type article
dc.type.genre thesis
dspace.entity.type Publication
relation.isOrgUnitOfPublication 047b23ca-7bd7-4194-b084-c4181d33d95d
thesis.degree.discipline Aerospace Engineering
thesis.degree.level thesis
thesis.degree.name Master of Science
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