An anisotropic constitutive model for 3D printed hydrogel-fiber composites

Purpose This study aims to focus on the effect of interlayer bonding and thermal decomposition on the mechanical properties of fused filament fabrication-printed polylactic acid specimens at high extrusion temperatures. Design/methodology/approach A printing process, that is simultaneous manufacturing of contour and specimen, is used to improve the printing accuracy at high extrusion temperatures. The effects of the extrusion temperature on the mechanical properties of the interlayer and intra-layer are evaluated via tensile experiments. In addition, the microstructure evolution affected by the extrusion temperature is observed using scanning electron microscopy. Findings The results show that the extrusion temperature can effectively improve the interlayer bonding property; however, the mechanical properties of the specimen for extrusion temperatures higher than 270°C may worsen owing to the thermal decomposition of the polylactic acid (PLA) material. The optimum extrusion temperature of PLA material in the three-dimensional (3D) printing process is recommended to be 250–270°C. Originality/value A temperature-compensated constitutive model for 3D printed PLA material under different extrusion temperatures is proposed. The present work facilitates the prediction of the mechanical properties of specimens at an extrusion temperature for different printing temperatures and different layers.

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MODELING AND SIMULATION OF THE CURING PROCESS OF EPOXY RESINS AND FIBER COMPOSITES

10.12783/asc36/35831 ◽

2021 ◽

Author(s):

ANASTASIA MULIANA

Keyword(s):

Constitutive Model ◽

Residual Stresses ◽

Elastic Moduli ◽

Processing Parameters ◽

Fiber Composites ◽

Curing Process ◽

Reinforced Composites ◽

Micromechanics Model ◽

Epoxy Curing ◽

Exothermic Process

This study discusses simulations of the curing process in epoxy and fiberreinforced polymer composites incorporating changes in the thermal and mechanical properties of epoxy during curing at various temperatures. A coupled constitutive model that includes an exothermic process from the cross-linking, heat conduction across the specimen and deformations of the specimen from the thermal expansion and shrinkage effects is formulated. The model is used to capture the curing process in the epoxy resin. The coupled constitutive model is then integrated into a micromechanics model of fiber-reinforced composites and used to study the influence of epoxy curing on the formation of residual stresses in the composites. Furthermore, the micromechanics model is also used to predict the macroscopic properties, i.e., elastic moduli, of the cured composites. The model can then be used to understand the influence of processing parameters, i.e., temperatures and pressure, on the formation of residual stresses and their consequences on the overall properties of cured composites.

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Implementation of an elastoplastic constitutive model for 3D-printed materials fabricated by stereolithography

Additive Manufacturing ◽

10.1016/j.addma.2020.101104 ◽

2020 ◽

Vol 33 ◽

pp. 101104 ◽

Cited By ~ 1

Author(s):

Shuheng Wang ◽

Yongbin Ma ◽

Zichen Deng ◽

Kai Zhang ◽

Shi Dai

Keyword(s):

Constitutive Model ◽

3D Printed ◽

Printed Materials ◽

Elastoplastic Constitutive Model

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A micropolar anisotropic constitutive model of cancellous bone from discrete homogenization

Journal of the Mechanical Behavior of Biomedical Materials ◽

10.1016/j.jmbbm.2012.07.012 ◽

2012 ◽

Vol 16 ◽

pp. 87-108 ◽

Cited By ~ 73

Author(s):

I. Goda ◽

M. Assidi ◽

S. Belouettar ◽

J.F. Ganghoffer

Keyword(s):

Constitutive Model ◽

Cancellous Bone ◽

Anisotropic Constitutive Model ◽

Discrete Homogenization

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An anisotropic constitutive model for immersogeometric fluid–structure interaction analysis of bioprosthetic heart valves

Journal of Biomechanics ◽

10.1016/j.jbiomech.2018.04.012 ◽

2018 ◽

Vol 74 ◽

pp. 23-31 ◽

Cited By ~ 16

Author(s):

Michael C.H. Wu ◽

Rana Zakerzadeh ◽

David Kamensky ◽

Josef Kiendl ◽

Michael S. Sacks ◽

...

Keyword(s):

Constitutive Model ◽

Heart Valves ◽

Interaction Analysis ◽

Fluid Structure Interaction ◽

Bioprosthetic Heart Valves ◽

Fluid Structure ◽

Structure Interaction ◽

Anisotropic Constitutive Model

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Simulation of Post Failure Response in Fiber Composites

Volume 8: Mechanics of Solids, Structures and Fluids; Vibration, Acoustics and Wave Propagation ◽

10.1115/imece2011-63019 ◽

2011 ◽

Cited By ~ 1

Author(s):

Badrinath Veluri ◽

Henrik Myhre Jensen

Keyword(s):

Finite Element ◽

Steady State ◽

Constitutive Model ◽

Failure Mechanism ◽

Inclination Angle ◽

Layered Materials ◽

Fiber Composites ◽

Finite Element Code ◽

Compressive Failure ◽

Localization Of Deformation

This study focuses on the compressive failure mechanism in the form of kinkband formation in fiber composites. Taking into account the non-linearities of the constituents, a constitutive model for unidirectional layered materials has been developed and incorporated as a user material in a commercially available finite element code to study effects of kinkband inclination angle and micro-geometry on kinkband formation. The localization of deformation into a single kinkband is studied. In the post failure regime a state is reached where deformation in the kinkband gets stabilized and the kinkband broadens under steady-state conditions.

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