An analytical–numerical framework for the study of ageing in fibre reinforced polymer composites

Seven linseed varieties were harvested at seven times before complete maturity. Microscale oilseed expressions were subsequently carried out on it. A pressure of 10 MPa was applied for 1 h under uniaxial stress. The results were characterized in terms of oil, water and mucilage content, harvest date and oil yield. The piston displacement versus time (creep curves) was described by a four-Kelvin-Voigt elements viscoelastic model. Parameters were derived from the model, such as the mechanical properties of seeds (compressibility moduli), showing that the viscoelastic model fits well the experimental data (R 2 ≈0.999). The modeling parameters were combined with some biochemical data in order to predict the kinetics of oil extraction.

Oil yield and compressibility modeling during microscale expression: Criteria for linseed breeding

The paper presents a rheological model capable of reproducing the temperature‐, stress‐, and time‐dependent strain component, which occurs in steel and aluminium during exposure to high temperature. The model is capable of providing the creep strain output for the primary, secondary, and tertiary creep phases for both steel and aluminium. Constitutive parameters of the rheological model are calibrated using 2 recent coupon test studies based on the European steel grade S275JR and aluminium grade EN6082AW T6, both of which are currently used in the construction industry. The calibrated constitutive parameters are valid within the temperature range, within which creep is expected to occur (400‐600°C for steel and 200‐300°C for aluminium). The rheological model proposed in the paper can easily be used for application in finite element–based computer codes.

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Development of a rheological model for creep strain evolution in steel and aluminium at high temperature

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Calibration of an Existing Creep Model for Analysis of Aluminium Members Exposed to Constant Temperature

A representation is introduced for the linear and non linear behaviour of concrete in the presence of time varying humidity, based in the state variables concept.

Non Linear Constitutive Equations for Concrete

A rheological model to describe non-linear deformations and failure is proposed. For the case of constant stress expressions of instantaneous and time-dependent deformations are developed. There is an acceptable agreement between theoretical predictions and experimental data.

G.J. Creus

Papers

A non-linear rheological model describing time-dependent deformations and failure