Characterization of Mode I and Mode II traction–separation laws for cohesive separation of uncured thermoset tows
| Autor: | Addis Kidane, Elsa Compton, William McMakin, Sreehari Rajan, Yasmeen Farzana, Zafer Gürdal, Michael A. Sutton, Roudy Wehbe |
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| Rok vydání: | 2019 |
| Předmět: |
Physics
Contact time Traction (engineering) Computational Mechanics Thermosetting polymer Geometry 02 engineering and technology Full field Characterization (mathematics) 01 natural sciences 010101 applied mathematics 020303 mechanical engineering & transports 0203 mechanical engineering Mechanics of Materials Displacement control Modeling and Simulation Constant load 0101 mathematics Double cantilever beam |
| Zdroj: | International Journal of Fracture. 221:25-38 |
| ISSN: | 1573-2673 0376-9429 |
| Popis: | As part of an effort to predict wrinkling of carbon-fiber tows during automated fiber placement, the cohesive zone traction–separation relations for two carbon fiber epoxy prepreg tows are quantified for Mode I and Mode II loading using a rigid double cantilever beam (RDCB) specimen. An explicit expression for normal traction versus normal separation ($$\upsigma \hbox { vs }\updelta _\mathrm{n}$$) and tangential traction versus tangential separation $$(\tau \hbox { vs }\updelta _\mathrm{t})$$ are derived using static equilibrium equations for an RDCB considering a compressive zone ahead of the process zone. The traction–separation relationships are in term of quantities that can be measured using a full field measurement technique (StereoDIC). The baseline traction–separation relationships in this work are obtained using conditions representative of those experienced by an uncured tow undergoing automated fiber placement (AFP) onto a substrate of a similar material with layup temperature $$\hbox {T} = 40\,{^{\circ }}\hbox {C}$$, pressure p = 1 MPa and contact time t = 1 s. The RDCB specimen is loaded in displacement control at a constant load line displacement rate of 0.3 mm/min. Speckle images for StereoDIC are captured using stereo vision systems equipped for capturing images of the RDCB specimen with a field of view of $$100\hbox { mm }\times 75\hbox { mm}$$. Analysis of the data obtained for Mode I and Mode II loading shows that the Mode I energy release rate $${\varvec{\mathscr {{G}}}}_\mathrm{I }= 120\hbox { J}/\hbox {m}^{2}$$ and Mode II energy release rate $${\varvec{\mathscr {{G}}}}_\mathrm{{II}} = 255\hbox { J}/\hbox {m}^{2}$$, with the maximum normal traction $${\varvec{\upsigma }}_\mathrm{\mathrm{max}} = 0.50\hbox { MPa}$$ and the maximum shear traction $${\varvec{\tau }}_\mathrm{\mathrm{max}} = 0.35\hbox { MPa}$$. |
| Databáze: | OpenAIRE |
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