TY  - JOUR
A1  - Zhang, Yongzheng
A1  - Ren, Huilong
T1  - Implicit implementation of the nonlocal operator method: an open source code
JF  - Engineering with computers
N2  - In this paper, we present an open-source code for the first-order and higher-order nonlocal operator method (NOM) including a detailed description of the implementation. The NOM is based on so-called support, dual-support, nonlocal operators, and an operate energy functional ensuring stability. The nonlocal operator is a generalization of the conventional differential operators. Combined with the method of weighed residuals and variational principles, NOM establishes the residual and tangent stiffness matrix of operate energy functional through some simple matrix without the need of shape functions as in other classical computational methods such as FEM. NOM only requires the definition of the energy drastically simplifying its implementation. The implementation in this paper is focused on linear elastic solids for sake of conciseness through the NOM can handle more complex nonlinear problems. The NOM can be very flexible and efficient to solve partial differential equations (PDEs), it’s also quite easy for readers to use the NOM and extend it to solve other complicated physical phenomena described by one or a set of PDEs. Finally, we present some classical benchmark problems including the classical cantilever beam and plate-with-a-hole problem, and we also make an extension of this method to solve complicated problems including phase-field fracture modeling and gradient elasticity material.
KW  - Strukturmechanik
KW  - Nonlocal operator method
KW  - Operator energy functional
KW  - Implicit
KW  - Dual-support
KW  - Variational principle
KW  - Taylor series expansion
KW  - Stiffness matrix
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220216-45930
UR  - https://link.springer.com/article/10.1007/s00366-021-01537-x
VL  - 2022
SP  - 1
EP  - 35
PB  - Springer
CY  - London
ER  - 
TY  - JOUR
A1  - Zhuang, Xiaoying
A1  - Huang, Runqiu
A1  - Liang, Chao
A1  - Rabczuk, Timon
T1  - A coupled thermo-hydro-mechanical model of jointed hard rock for compressed air energy storage
JF  - Mathematical Problems in Engineering
N2  - Renewable energy resources such as wind and solar are intermittent, which causes instability when being connected to utility grid of electricity. Compressed air energy storage (CAES) provides an economic and technical viable solution to this problem by utilizing subsurface rock cavern to store the electricity generated by renewable energy in the form of compressed air. Though CAES has been used for over three decades, it is only restricted to salt rock or aquifers for air tightness reason. In this paper, the technical feasibility of utilizing hard rock for CAES is investigated by using a coupled thermo-hydro-mechanical (THM) modelling of nonisothermal gas flow. Governing equations are derived from the rules of energy balance, mass balance, and static equilibrium. Cyclic volumetric mass source and heat source models are applied to simulate the gas injection and production. Evaluation is carried out for intact rock and rock with discrete crack, respectively. In both cases, the heat and pressure losses using air mass control and supplementary air injection are compared.
KW  - Energiespeicherung
KW  - Druckluft
KW  - Kaverne
KW  - Modellierung
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170428-31726
ER  -