Results 51 to 60 of about 1,439 (183)

Robust Position Control of an Electro‐Hydraulic Actuator via Metaheuristic Optimization of a Fractional‐Order PID Controller

International Journal of Mechanical System Dynamics, EarlyView.
ABSTRACT In this study, a robust position control strategy is presented for a two‐stage electro‐hydraulic actuator system using a fractional‐order proportional–integral–derivative (FOPID) controller tuned by Kirchhoff's law algorithm (KLA). Electro‐hydraulic systems exhibit strong nonlinearities, parameter uncertainties, and external disturbances ...
Ridvan Firat Cinar, Davut Izci, Serdar Ekinci, Mohammad Salman, Mohammad Al‐Rabayah, Ali Akdagli, Ali Yildiz, Filiz Karaomerlioglu, Gökhan Yüksek   +8 more
wiley   +1 more source

A Coupled Extended Finite Element–Cohesive Zone Model for Hydraulic Fracture Propagation Under Poroelastic Effects Across Different Propagation Regimes

International Journal for Numerical and Analytical Methods in Geomechanics, EarlyView.
ABSTRACT Numerical simulation of hydraulic fracturing remains challenging due to the strong coupling between geomechanics and fluid flow when modelling multiple physical mechanisms of rock deformation, fracture evolution and fluid leak‐off. This study develops a coupled hydraulic fracture propagation framework that combines the extended finite element ...
Ran Tao, Juliana Y. Leung, Samer Adeeb
wiley   +1 more source

A Coupled Chemohydraulic Model of a Hydration Experiment

International Journal for Numerical and Analytical Methods in Geomechanics, EarlyView.
ABSTRACT This article presents a model for the hydration of periclase into brucite during water infiltration into a dry, pure periclase core. The hydration process proceeds in two stages. In Phase I, an infiltration front advances through the core while simultaneously triggering the hydration reaction.
Emmanuel Detournay, Vaughan Voller
wiley   +1 more source

Numerical Modeling of Geological Fault Reactivation Using Sequential Coupling Strategies

International Journal for Numerical and Analytical Methods in Geomechanics, EarlyView.
ABSTRACT The interaction between fluid flow and mechanical deformation in fault zones can lead to processes of fault reactivation, triggering potential geomechanical problems such as seismicity, well collapse, fluid migration to shallower layers, and aggravated surface subsidence.
Julio Rueda, Cristian Mejia, Roberto Quevedo, Deane Roehl   +3 more
wiley   +1 more source

Constant sign and nodal solutions for singular quasilinear elliptic systems

We consider singular quasilinear elliptic systems with homogeneous Dirichlet boundary condition. Using Leray-Schauder topological degree, combined with the sub-supersolutions method and suitable truncation arguments, we establish the existence of at least three nontrivial solutions, two of which are of opposite constant sign.
Medjoudj, Nouredine, Moussaoui, Abdelkrim   +1 more
openaire   +2 more sources

Application of Non‐Isothermal Network Theory With Curved‐Channel Element Characteristics to Predict Melt Conveying in High‐Performance Single‐Screw Extruders

Journal of Polymer Science, EarlyView.
This study presents a fast and accurate calculation tool to predict conveying of polymer melts in single‐screw extruders. Integrating generalized sub‐models into network theory allows to represent the complex screw shapes and material behavior more realistically. Tests on an industrial extruder show close agreement with experiments, outperforming older
Daniel Herzog, Wolfgang Roland, Christian Marschik, Gerald Berger‐Weber   +3 more
wiley   +1 more source

Nodal solutions for (p, 2)-equations

In this paper, we study a nonlinear elliptic equation driven by the sum of a p-Laplacian and a Laplacian ((p, 2)-equation), with a Carathéodory (p − 1)-(sub-)linear reaction.
Aizicovici, S., Staicu, V., Papageorgiou, N. S.   +2 more
core   +1 more source

How interference between the North Atlantic Oscillation and the tropical Indo‐Pacific convection modulates wave trains along the subtropical jet: Impacts on the Asian winter climate

Quarterly Journal of the Royal Meteorological Society, EarlyView.
This study reveals that the combined effects of the North Atlantic Oscillation (NAO) and anomalous Indo‐Pacific Walker circulation on the excitation of the wave train along the wintertime subtropical jet strongly depend on their phase combination. Their impacts interfere constructively or destructively over South Asia, leading to notable differences in
Yuki Asazuma, Masaya Kuramochi, Hiroaki Ueda   +2 more
wiley   +1 more source

The Pier Luigi Nervi's concrete structure of Palazzetto dello Sport: Modeling and dynamic characterization

Structural Concrete, EarlyView.
Abstract This paper presents a numerical and experimental study aimed at the modeling and dynamic characterization of the reinforced concrete structure of the Palazzetto dello Sport in Rome, designed and by Pier Luigi Nervi with Annibale Vitellozzi, and built by Nervi & Bartoli contractors in 1956‐57.
Jacopo Ciambella, Gianluca Ranzi, Francesco Romeo   +2 more
wiley   +1 more source

Reverse engineering strut‐and‐tie models for assessing reinforced concrete structures

Structural Concrete, EarlyView.
Abstract Strut‐and‐tie models enable the design of reinforced concrete structures with static or geometrical discontinuities, providing interpretability and control over the load path. These models are valuable for designing discontinuity regions of new structures and for validating nonlinear finite‐element analysis results. However, developing a strut‐
Karin Yu, Walter Kaufmann
wiley   +1 more source