Dong Yijia

Hohai University

Water leakage is a critical factor reflecting the structural safety of shield tunnels. Computer vision provides new opportunities to overcome the shortcomings of manual visual inspection and realize automatic detection of water leakage regions. In this study, we propose a leakage segmentation model with an encoder–decoder structure. The encoder ado...

In this paper, an element-based deep learning approach named DeepFEM for solving nonlinear partial differential equations (PDEs) in solid mechanics is developed to reduce the number of sampling points required for training the deep neural network. Shape functions are introduced into deep learning to approximate the displacement field within the ele...

This work presents an adaptive hierarchical multiscale approach for modeling the trans-scale damage evolution in concrete. The problem domain represented by an adaptive hierarchical multiscale finite element (FE) model is decomposed into two regions, namely the macroscopic elastic region and the multiscale critical region prone to damage. The forme...

The fully-graded concrete (FGC) is widely used in hydraulic mass concrete structures. An exquisite mesoscale model for FGC is essential for accurately simulating its complex damage and cracking behavior. However, due to the presence of massive aggregates and the requirement of high aggregate volume fraction, it is still challenging to generate the...

This study explores a bioinspired, low-cost, and ubiquitous biomolecule-tannic acid (TA)-as a small-dose molecular-scale admixture to modify the nano-and micro-structures of the major hydration product of ordinary Portland cement (OPC) (e.g., calcium silicate hydrate (C-S-H)) so that the performance and eco-efficiency of the concrete can be signifi...

Accurate prediction of multiscale fracture process of concrete relies on modeling of concrete mesostructures. Though high-resolution yet realistic mesostructures can be obtained by CT technique, the size limitation of reconstructed mesostructures is still an outstanding task. In this paper, a novel method of generating synthetic mesostructures of c...

Ordinary state-based peridynamics (OSPD) is a promising computational method to analyze damage and fracture process because its equation of motion is still satisfied at the presence of discontinuities. Though OSPD has been introduced to evaluate mesoscopic behavior of concrete, there are many unsolved issues to tackle quasi-brittle behavior of meso...

The non-ordinary state-based peridynamics (NSPD) is a promising method for fracture analysis, and it can incorporate the constitutive relationship of classical continuum mechanics in peridynamics. However, the high computational cost is one of the main reasons limiting its usage. To improve computational efficiency of NSPD, a stability-enhanced per...

As a nondestructive imaging technology, X-ray CT has become an effective tool for studying the microstructural damage of concrete. However, autonomous identification and segmentation of microstructural cracks remains a challenge due to the same greyscales of voids and cracks in CT images. To address this problem, this paper develops a new method fo...

Frost resistance of cementitious materials is enhanced with introduction of a series of randomly dispersed air-entrained voids. While it is understood that the improvement of frost resistance is due to the functions of cryo-suction and water reservoir of the voids, their heterogeneous, random distribution has not been considered in the modeling fra...

This paper investigated and simulated the mechanical effect of root reinforcing soil and stabilizing slope. The unconfined compression test was used to investigate the reinforcement soil behavior of herb roots. This paper used the 3D finite element to quantify the mechanical effect of the herb root for slope’s stability in terms of the safety facto...

Concrete structures in cold regions are exposed to cyclic freezing and thawing environment, leading to degraded mechanical and fracture properties of concrete due to microstructural damage. While the X-ray micro-/nano-computed tomography technology has been implemented to directly observe concrete microstructure and characterize local damage in rec...

The continuous and discontinuous deformation analysis is essential for the stability analysis of the anchor bar-surrounding rock masses system. To eliminate the open-close iteration and the penalty factor of the 3D-DDA, the CDDA is proposed to extend into the three-dimensional block system. Then a novel simulation approach, the coupling method of 3...

The key factors of the damping solvent extraction method are artificial damping coefficient and size of unbounded medium. The solutions of the key factors have great influences on the accuracy and the efficiency of the dynamic simulation of the interaction of structure-foundation. To avoid the randomness and uncertainty of the key factors, the valu...

Subjected to construction situations, engineers of some lock head projects do not perform adiabatic temperature rising test to determine thermal parameters of concrete. To solve this problem, this paper proposed an inverse analysis method of lock head thermal parameters based on BP neural networks. Firstly, combinations of concrete thermal paramete...