TY  - JOUR
A1  - Ren, Huilong
A1  - Zhuang, Xiaoying
A1  - Oterkus, Erkan
A1  - Zhu, Hehua
A1  - Rabczuk, Timon
T1  - Nonlocal strong forms of thin plate, gradient elasticity, magneto-electro-elasticity and phase-field fracture by nonlocal operator method
JF  - Engineering with Computers
N2  - The derivation of nonlocal strong forms for many physical problems remains cumbersome in traditional methods. In this paper, we apply the variational principle/weighted residual method based on nonlocal operator method for the derivation of nonlocal forms for elasticity, thin plate, gradient elasticity, electro-magneto-elasticity and phase-field fracture method. The nonlocal governing equations are expressed as an integral form on support and dual-support. The first example shows that the nonlocal elasticity has the same form as dual-horizon non-ordinary state-based peridynamics. The derivation is simple and general and it can convert efficiently many local physical models into their corresponding nonlocal forms. In addition, a criterion based on the instability of the nonlocal gradient is proposed for the fracture modelling in linear elasticity. Several numerical examples are presented to validate nonlocal elasticity and the nonlocal thin plate.
KW  - Bruchmechanik
KW  - Elastizität
KW  - Peridynamik
KW  - energy form
KW  - weak form
KW  - peridynamics
KW  - variational principle
KW  - explicit time integration
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211207-45388
UR  - https://link.springer.com/article/10.1007/s00366-021-01502-8
VL  - 2021
SP  - 1
EP  - 22
ER  - 
TY  - JOUR
A1  - Amani, Jafar
A1  - Saboor Bagherzadeh, Amir
A1  - Rabczuk, Timon
T1  - Error estimate and adaptive refinement in mixed discrete least squares meshless method
JF  - Mathematical Problems in Engineering
N2  - The node moving and multistage node enrichment adaptive refinement procedures are extended in mixed discrete least squares meshless (MDLSM) method for efficient analysis of elasticity problems. In the formulation of MDLSM method, mixed formulation is accepted to avoid second-order differentiation of shape functions and to obtain displacements and stresses simultaneously. In the refinement procedures, a robust error estimator based on the value of the least square residuals functional of the governing differential equations and its boundaries at nodal points is used which is inherently available from the MDLSM formulation and can efficiently identify the zones with higher numerical errors. The results are compared with the refinement procedures in the irreducible formulation of discrete least squares meshless (DLSM) method and show the accuracy and efficiency of the proposed procedures. Also, the comparison of the error norms and convergence rate show the fidelity of the proposed adaptive refinement procedures in the MDLSM method.
KW  - Elastizität
KW  - Fehlerabschätzung
KW  - MDLSM method
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170413-31181
ER  -