Investigating Effects of Heterogeneity and Fracture Distribution on Two-Phase Flow in Fractured Reservoir with adaptive time strategy

Modeling of fluid flow in porous media is a pillar in geoscience applications. Previous studies have revealed that heterogeneity and fracture distribution have considerable influence on fluid flow. In this work, a numerical investigation of two-phase flow in heterogeneous fractured reservoir is presented. First, the discrete fracture model is...

Physics-based and data-driven modeling for stability evaluation of buried structures in natural clays

This study presents a hybrid framework to predict stability solutions of buried structures under active trapdoor conditions in natural clays with anisotropy and heterogeneity by combining physics-based and data-driven modeling. Finite-element limit analysis (FELA) with a newly developed anisotropic undrained shear (AUS) failure criterion is...

Numerical study of the delamination toughening effect of weakening and toughening patche

A numerical study on the feasibility of using patches of interface weakening or toughening material to trigger multiple delaminations toughening laminated composite structures against delamination is presented. The studies use an adaptive refinement formulation that uses cohesive elements to model delamination initiation and propagation. A DCB...

Participatory approaches in the adaptive reuse of two Dutch private-led cultural heritage projects: role of the local communities

There is increasing debate concerning citizen participation in the reuse and transformation of heritage sites. However, the question of why and how participatory approaches are explored in private-led heritage adaptive reuse receives limited attention. The paper shows why the communities should play an essential role in the adaptive reuse of...

Delamination toughening of composite laminates using weakening or toughening interlaminar patches to initiate multiple delaminations: A numerical study

A numerical study on toughening laminated composite materials against delamination by initiating multiple interlaminar cracks is presented. Different configurations of interface toughening and weakening patches, that modify the interface properties at selected locations, are investigated as a way to trigger multiple delaminations. Both...

An adaptive floating node based formulation for the analysis of multiple delaminations under high cycle fatigue loading

A novel efficient numerical formulation for the analysis of multiple fatigue-driven delamination cracks is presented. A cohesive zone model is used in combination with an Adaptive Refinement Scheme (ARS) and an Adaptive Floating Node Method (A-FNM) element that refine the model effectively during the analysis. Novel techniques are proposed to...

Undrained stability of pit-in-pit braced excavations under hydraulic uplift

Pit-in-pit (PIP) excavations in an aquifer–aquitard system likely undergo catastrophic failures under the hydraulic uplift, the associated undrained stability problem, however, has not been well analyzed in the past. To this end, a hypothetical model of PIP braced excavation in typical soil layers of Shanghai, China is developed using the...

An adaptive floating node based formulation for the analysis of multiple delaminations under quasi-static loading

A novel and efficient numerical formulation for the modelling of multiple delaminations growth in laminated composite materials subjected to quasi-static loading is presented. The proposed formulation alleviates the high computational cost associated with models featuring cohesive elements by using a novel Adaptive Refinement Scheme and an...

基于强化学习补偿的地面无人战车行进间跟瞄自适应控制

To deal with the nonlinear interference caused by chassis movement and road surface undulations with the tracking and aiming of unmanned combat ground vehicles, a tracking and aiming adaptive control method for unmanned combat ground vehicles on the move based on reinforcement learning compensation is proposed. This method consists of a main...

Prescribed-performance tracking for high-power nonlinear dynamics with time-varying unknown control coefficients

Prescribed-performance control (PPC) for high-power dynamics with time-varying unknown control coefficients requires to address two open problems: (a) given a Nussbaum function, which properties hold for the power of the Nussbaum function? (b) to avoid high gains, how to design a switching gain that increases only when the tracking error is...

Jensen–Shannon Distance-Based Filter and Unsupervised Evaluation Metrics for Polarimetric Weather Radar Processing

An effective filtering technique is required for rainfall rate measurement by weather radar. A Jensen–Shannon distance (JSD)-based thresholding filter is proposed to mitigate nonmeteorological signals, either in clear air or rain situations. This algorithm classifies range-Doppler bins into two classes, hydrometeors and nonhydrometeors, based on...

Neuro-Adaptive Cooperative Tracking Rendezvous of Nonholonomic Mobile Robots

This brief proposes a neuro-adaptive method for the unsolved problem of cooperative tracking rendezvous of nonholonomic mobile robots (NMRs) subject to uncertain and unmodelled dynamics. A hierarchical cooperative control framework is proposed, which consists of a novel distributed estimator along with local neuro-adaptive tracking...

Change Detection Algorithm for Multi-Temporal Remote Sensing Images Based on Adaptive Parameter Estimation

This paper proposes a multioral image change detection algorithm based on adaptive parameter estimation, which is used to solve the problems of severe interference of coherent speckle noise and the retention of detailed information about changing regions in synthetic aperture radar remote sensing images. The change area in the initial...

Overcoming the cohesive zone limit in composites delamination: modeling with slender structural elements and higher-order adaptive integration

Cohesive element (CE) is a well-established finite element for fracture, widely used for the modeling of delamination in composites. However, an extremely fine mesh is usually needed to resolve the cohesive zone, making CE-based delamination analysis computationally prohibitive for applications beyond the scale of lab coupons. In this work, a...

Relaxing the control-gain assumptions of DSC design for nonlinear MIMO systems

This work focuses on adaptive neural dynamic surface control (DSC) for an extended class of nonlinear MIMO strict-feedback systems whose control gain functions are continuous and possibly unbounded. The method is based on introducing a compact set which is eventually proved to be an invariant set: thanks to this set, the restrictive...

Adaptive floating node method for modelling cohesive fracture of composite materials

The cohesive element has been widely employed to model delamination and matrix cracking in composite materials. However, an extremely fine mesh along the potential crack path is required to achieve accurate predictions of stresses within the cohesive zone. A sufficient number of cohesive elements must be present within the cohesive zone ahead...

Equilibrium running principle analysis on an adaptive cycle engine

As an evolutional concept of variable cycle engine, the adaptive cycle engine draws widely attention with high expectations. It combines a variable geometry schedule and component matching principles to demonstrate its advantages such as avoiding severe inlet spillage drag and the wide variable cycle characteristics. Thus, this paper aims at...