Tensile properties of all-polymeric syntactic foam composites: Experimental characterization and mathematical modellingCitation formats

Standard

Tensile properties of all-polymeric syntactic foam composites: Experimental characterization and mathematical modelling. / Yousaf, Zeshan; Morrison, Neil F.; Parnell, William J.

In: Composites. Part B: Engineering, Vol. 231, 109556, 15.02.2022.

Research output: Contribution to journalArticlepeer-review

Harvard

APA

Vancouver

Author

Bibtex

@article{f7382daff9f34ef8a585aafdadc05a0c,
title = "Tensile properties of all-polymeric syntactic foam composites: Experimental characterization and mathematical modelling",
abstract = "All-polymer syntactic foams are studied under large strain cyclic and monotonic tensile loading in order to reveal their tensile stress-strain behaviour, recoverability, tensile strength, and elongation at break. The syntactic foam under study here consists of hollow thermoplastic microspheres (HTMs) of two distinct grades (551 and 920), with distributions of mean-wall thicknesses and diameters, embedded inside a polyurethane matrix in various volume fractions. Cyclic loading-unloading curves are recorded, revealing the level of viscoelasticity exhibited by the materials (which becomes a stronger effect with increasing volume fractions of HTMs) and indicating the level of repeatability of loading under large strain. Samples are also subjected to monotonic tensile loading in order to study their elongation at break. Higher volume fractions of HTMs increase the stiffness of the material and whilst it is observed that the materials are highly elastic over a wide range of tensile strains, damage arises at lower levels of strain for more highly filled materials. The HTM syntactic foams thus exhibit lower breaking strains compared to the neat matrix, which is attributed to matrix-microsphere interfacial debonding. Furthermore, by employing optimization techniques, linear elastic properties of the microspheres and an average shell thickness of the 551 grade are inferred by comparing experimental results to predictions from the Generalized Self-Consistent Method, incorporating polydispersity data on the size distribution of the microspheres. These results complement previous work which involved direct experimental measurements of the 920 grade shell thickness. Results also indicate that the characterization of microsphere properties is not critically dependent on access to high resolution microsphere diameter distribution data, provided that an accurate representative mean diameter is known. Finally, the thermal degradation of the samples is studied by using thermogravimetric analysis (TGA) which reveals that HTMs can be added to a polyurethane matrix without significantly affecting the thermal stability of the matrix material.",
keywords = "Damage tolerance, Particle reinforced composites, Syntactic foams, Tensile properties, Thermal analysis",
author = "Zeshan Yousaf and Morrison, {Neil F.} and Parnell, {William J.}",
year = "2022",
month = feb,
day = "15",
doi = "10.1016/j.compositesb.2021.109556",
language = "English",
volume = "231",
journal = "Composites. Part B: Engineering",
issn = "1359-8368",
publisher = "Elsevier BV",

}

RIS

TY - JOUR

T1 - Tensile properties of all-polymeric syntactic foam composites: Experimental characterization and mathematical modelling

AU - Yousaf, Zeshan

AU - Morrison, Neil F.

AU - Parnell, William J.

PY - 2022/2/15

Y1 - 2022/2/15

N2 - All-polymer syntactic foams are studied under large strain cyclic and monotonic tensile loading in order to reveal their tensile stress-strain behaviour, recoverability, tensile strength, and elongation at break. The syntactic foam under study here consists of hollow thermoplastic microspheres (HTMs) of two distinct grades (551 and 920), with distributions of mean-wall thicknesses and diameters, embedded inside a polyurethane matrix in various volume fractions. Cyclic loading-unloading curves are recorded, revealing the level of viscoelasticity exhibited by the materials (which becomes a stronger effect with increasing volume fractions of HTMs) and indicating the level of repeatability of loading under large strain. Samples are also subjected to monotonic tensile loading in order to study their elongation at break. Higher volume fractions of HTMs increase the stiffness of the material and whilst it is observed that the materials are highly elastic over a wide range of tensile strains, damage arises at lower levels of strain for more highly filled materials. The HTM syntactic foams thus exhibit lower breaking strains compared to the neat matrix, which is attributed to matrix-microsphere interfacial debonding. Furthermore, by employing optimization techniques, linear elastic properties of the microspheres and an average shell thickness of the 551 grade are inferred by comparing experimental results to predictions from the Generalized Self-Consistent Method, incorporating polydispersity data on the size distribution of the microspheres. These results complement previous work which involved direct experimental measurements of the 920 grade shell thickness. Results also indicate that the characterization of microsphere properties is not critically dependent on access to high resolution microsphere diameter distribution data, provided that an accurate representative mean diameter is known. Finally, the thermal degradation of the samples is studied by using thermogravimetric analysis (TGA) which reveals that HTMs can be added to a polyurethane matrix without significantly affecting the thermal stability of the matrix material.

AB - All-polymer syntactic foams are studied under large strain cyclic and monotonic tensile loading in order to reveal their tensile stress-strain behaviour, recoverability, tensile strength, and elongation at break. The syntactic foam under study here consists of hollow thermoplastic microspheres (HTMs) of two distinct grades (551 and 920), with distributions of mean-wall thicknesses and diameters, embedded inside a polyurethane matrix in various volume fractions. Cyclic loading-unloading curves are recorded, revealing the level of viscoelasticity exhibited by the materials (which becomes a stronger effect with increasing volume fractions of HTMs) and indicating the level of repeatability of loading under large strain. Samples are also subjected to monotonic tensile loading in order to study their elongation at break. Higher volume fractions of HTMs increase the stiffness of the material and whilst it is observed that the materials are highly elastic over a wide range of tensile strains, damage arises at lower levels of strain for more highly filled materials. The HTM syntactic foams thus exhibit lower breaking strains compared to the neat matrix, which is attributed to matrix-microsphere interfacial debonding. Furthermore, by employing optimization techniques, linear elastic properties of the microspheres and an average shell thickness of the 551 grade are inferred by comparing experimental results to predictions from the Generalized Self-Consistent Method, incorporating polydispersity data on the size distribution of the microspheres. These results complement previous work which involved direct experimental measurements of the 920 grade shell thickness. Results also indicate that the characterization of microsphere properties is not critically dependent on access to high resolution microsphere diameter distribution data, provided that an accurate representative mean diameter is known. Finally, the thermal degradation of the samples is studied by using thermogravimetric analysis (TGA) which reveals that HTMs can be added to a polyurethane matrix without significantly affecting the thermal stability of the matrix material.

KW - Damage tolerance

KW - Particle reinforced composites

KW - Syntactic foams

KW - Tensile properties

KW - Thermal analysis

U2 - 10.1016/j.compositesb.2021.109556

DO - 10.1016/j.compositesb.2021.109556

M3 - Article

VL - 231

JO - Composites. Part B: Engineering

JF - Composites. Part B: Engineering

SN - 1359-8368

M1 - 109556

ER -