A method for calibration of the Hyperplastic Accelerated Ratcheting Model (HARM)

Abstract

This paper presents an analytical methodology for calibration of the Hyperplastic Accelerated Ratcheting Model (HARM) [3], based on a closed-form expression for the accumulation of ratcheting strain with cyclic history. The proposed method requires the fit of one test response and of a few continuous cyclic tests. The initial motivation for this work is the calibration of models for the design of piles subjected to longterm cyclic lateral loading, and the test results from Abadie, Byrne [1], [2] are used for calibration and proofing of the model. Nevertheless, the method is applicable to other problems of similar behaviour.

Modeling Lifetime Performance of Monopile Foundations for Offshore Wind Applications

“…The calibration method is outlined in Abadie et al (2019), based on the experimental results of Abadie et al (2017), with the key steps of the method summarized in Appendix B.…”

“…The properties of the test piles are given in Table 2, while the load sequences for CM6 and CM5 are shown in Table 3 and Table 4 respectively CM6 involves a short series of cycles of three load-sets at increasing load magnitudes, while CM5 involves a more extensive series of load-sets, of larger numbers of cycles. Calibration follows the steps outlined by Abadie et al (2019), in which the model is expressed in terms of a normalized "stress" and normalized "strain". For the 0-D model:…”

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This paper explores the application of a numerical method for modelling pseudorandom cyclic loading, at very large cycle numbers, to the design of offshore wind turbine foundations. The work expands the development of a novel constitutive modelling framework, HARM, described by Houlsby et al ( 2017), with a calibration method outlined in Abadie et al (2019). HARM captures both the non-linear hysteretic behavior during cycling and the accumulation of permanent deformation (ratcheting) with large cycle numbers in a rigorous, yet computationally efficient manner, enabling the computation of foundation response over a lifetime of loading.

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From cyclic sand ratcheting to tilt accumulation of offshore monopiles: 3D FE modelling using SANISAND-MS

“…-methods based on '0D' modelling of monopile-soil interaction. In this approach, distributed/continuum geotechnical mechanisms are lumped into a single macro-element formulated in terms of only a few pairs Abadie et al, 2019b). Non-linear monopile macro-elements have also been used to account for soilfoundation interaction effects in the dynamic analysis of OWTs (Page et al, 2019), and may potentially be extended to tackle cyclic loading conditions (di Prisco & Pisanò, 2011);…”

Cyclic performance of a monopile in spatially variable clay using an advanced constitutive model

“…Cycleby-cycle assessment of monopile behaviour requires more advanced analysis, with constitutive models capable of capturing the governing mechanisms. Houlsby et al [29] introduced a hyperplasticity model for the general ratcheting response of a structure under cyclic loads, describing the continuous accumulation of permanent deformations with number of cycles, and this was calibrated by Abadie et al [2] for monopiles in dry sand. In saturated sands, coupled hydro-mechanical finite element (FE) analyses incorporating multi-surface plasticity models have shown that monopiles under cyclic loading can generate a partially drained response in the soil, with monopile performance influenced by transient pore pressure generation and dilative and contractive (liquefying) responses [4,11].…”