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ردیف | عنوان | نوع |
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1 |
On the scaling law of JKR contact model for coarse-grained cohesive particles
در قانون مقیاس بندی مدل تماس JKR برای ذرات منسجم دانه درشت -2020 The computational cost of using discrete element method (DEM) simulations for particulate processes
with fine and cohesive particles is enormously large. To overcome this limitation, various coarse-grain
DEM models have been developed which use a smaller number of larger sized particles. Although the
computational cost is significantly reduced, the accuracy of the simulations depends on the underlying
scaling law. We propose a scaling of the Johnson-Kendall-Roberts (JKR) contact model for adhesive viscoelastic
particles. A scaling law using a single Bond number or Cohesion number criterion is insufficient
to keep the motion of the coarse-grained particles the same as the original particles. The scaling law in
this work is developed based on mass, momentum and energy conservation, and achieves good consistency
between the kinematic characteristics of the coarse-grained and original particles. The simulated
effective coefficients of restitution were compared for a range of particle-wall impact velocities and validated
against experimental data. Keywords: Discrete element method | Coarse-grain model | JKR contact model | Cohesive materials | Scaling-up |
مقاله انگلیسی |
2 |
Determination of the interfacial cohesive material law for SRG composites bonded to a masonry substrate
تعیین قانون ماده چسبندگی میان سطحی برای کامپوزیت های SRG که به یک بستر سنگ تراشی متصل می شوند-2020 Fiber reinforced cementitious matrix (FRCM) composites, also known as textile reinforced matrix
(TRM) composites, are a suitable alternative to fiber reinforced polymer (FRP) composites to
strengthen reinforced concrete and masonry structures. In the toolbox of FRCMs, a recentlydeveloped
composite that employs high-strength steel fibers embedded in a hydraulic mortar is
particular appealing for applications on historical masonry constructions. This type of composite
is known as steel reinforced grout (SRG). In this paper, an extensive experimental work is presented.
Single-lap shear tests are performed to study the debonding of SRG strips from a masonry
substrate, which is the critical failure mode for strengthening applications. For SRGs, debonding
typically occurs at the fiber-matrix interface. A large scatter of the experimental results is observed,
which is related to the variability of hydraulic mortars and their ability to impregnate the
fibers. Although strain gauges can be applied directly to the fibers to obtain the experimental
strain profile along the fibers, because of the presence of the matrix these measurements are
complex and in some cases not reliable. Thus, indirect method based on the global response of the
test is proposed to obtain the interfacial properties. Keywords: SRG | Debonding | Cohesive Material Law | Masonry |
مقاله انگلیسی |