Nagy alakváltozású rugalmas problémák magasabb rendű peridinamikus modellezése

Ladányi, Gábor and Gonda, Viktor (2021) Nagy alakváltozású rugalmas problémák magasabb rendű peridinamikus modellezése. DUNAKAVICS, 9 (4). pp. 75-100. ISSN 2064-5007

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Abstract

Machine components made of plastics are subjected to complex mechanical loads during manufacturing as well as during their service life. Under these loadings, voids and cracks can nucleate and propagate in components and can decrease the lifetime of the product. Modelling of crack initiation, propagation and branching is difficult in classical finite element analysis (FEM). Nevertheless the quite new results of Extended FEM and meshless methods, for ductile materials and large deformations it is still open for further research. Surface mounted electronic devices (SMD) are subjected to complex thermo-mechanical loads during manufacturing as well as during their service life. Even during manufacturing, voids and cracks can nucleate in soldered joints and also in components such as capacitors, made of brittle materials. An initial damage can have a detrimental effect on the lifetime of the product. Modelling of crack initiation and propagation is difficult in classical finite element analysis (FEM), due to the singularity of the mathematical functions in the differential analysis. Extended FEM (X-FEM) and meshless methods were developed to overcome these problems, nevertheless thermo-mechanical coupling of cracks and crack branching is still open for further research. Peridynamic Continuum Modelling (PCM) is dedicated to solve the crack initiation, propagation and fracture by integral equations. In original bond-based peridynamics, tearable springs are defined between all the couples of material points of the continuum, while in a more advanced formulation as a state-based modelling, a force vector is defined as well. In this work, the state based peridynamic model of the coupled thermo-mechanical problem was developed, and applied to detect initiation and propagation of cracks during cooling of a printed circuit board (PCB) after SMD soldering in a wave soldering machine. One of our goals in the research was to create a reliable and faster peridynamic solver suitable for describing crack formation and propagation. The creation of nodes in the simple case studies set out for the task thanks to the simple geometric design - did not require significant time. In the case of later tasks with more complex geometries, questions may still arise here. Peridynamic equations of motion, equilibrium, or thermal conductivity are nonlocal in nature, and the acceleration / equilibrium or temperature of an arbitrarily selected material point is affected not only by a direct but also by a finite distance environment. Peridynamic connections of nodes are understood to mean neighbors located within this distance.

Item Type:	Article
Uncontrolled Keywords:	Crack initiation; Peridynamic; Continuum modelling; Thermo-mechanical loads; repedéskeletkezés, Extended FEM és a háló nélküli módszerek, termomechanikai terhelések, X-FEM, peridinamikus kontinuum modellezés, peridinamikus mozgás
Divisions:	Műszaki Intézet
Depositing User:	Gergely Beregi
Date Deposited:	04 May 2021 11:15
Last Modified:	04 May 2021 11:16
URI:	http://publication.repo.uniduna.hu/id/eprint/753
MTMT:	31983593

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