Parallel Particle Advection and Lagrangian Analysis for 3D-PLI Fiber Orientation Maps

A series of computational models and simulations were conducted for determining the dynamic responses of a solid metal projectile impacting a target under a prescribed high strain rate loading scenario in three-dimensional space. The focus of this study was placed on two different modeling techniques within finite element analysis available in the Abaqus software suite. The first analysis technique relied heavily on more traditional Lagrangian analysis methods utilizing a fixed mesh, while still taking advantage of the finite difference integration present under the explicit analysis approach. A symmetry reduced model using the Lagrangian coordinate system was also developed for comparison in physical and computational performance. The second analysis technique relied on a mixed model that still made use of some Lagrangian modeling, but included smoothed particle hydrodynamics techniques as well, which are mesh free. The inclusion of the smoothed particle hydrodynamics was intended to address some of the known issues in Lagrangian analysis under high displacement and deformation. A comparison of the models was first performed against experimental results as a validation of the models, then the models were compared against each other based on closeness to experimentation and computational performance.

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Modeling of Bridging Law for Bundled Aramid Fiber-Reinforced Cementitious Composite and its Adaptability in Crack Width Evaluation

Materials ◽

10.3390/ma14010179 ◽

2021 ◽

Vol 14 (1) ◽

pp. 179

Author(s):

Daiki Sunaga ◽

Takumi Koba ◽

Toshiyuki Kanakubo

Keyword(s):

Fiber Orientation ◽

Crack Width ◽

Volume Fraction ◽

Characteristic Point ◽

Crack Opening ◽

Aramid Fiber ◽

Cementitious Composite ◽

Fiber Reinforced ◽

Cross Sectional ◽

Bridging Law

Tensile performance of fiber-reinforced cementitious composite (FRCC) after first cracking is characterized by fiber-bridging stress–crack width relationships called bridging law. The bridging law can be calculated by an integral calculus of forces carried by individual fibers, considering the fiber orientation. The objective of this study was to propose a simplified model of bridging law for bundled aramid fiber, considering fiber orientation for the practical use. By using the pullout characteristic of bundled aramid fiber obtained in the previous study, the bridging laws were calculated for various cases of fiber orientation. The calculated results were expressed by a bilinear model, and each characteristic point is expressed by the function of fiber-orientation intensity. After that, uniaxial tension tests of steel reinforced aramid-FRCC prism specimens were conducted to obtain the crack-opening behavior and confirm the adaptability of the modeled bridging laws in crack-width evaluation. The experimental parameters are cross-sectional dimensions of specimens and volume fraction of fiber. The test results are compared with the theoretical curves calculated by using the modeled bridging law and show good agreements in each parameter.

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Finite element modelling of fully-coupled flow/fiber-orientation effects in Polymer Composite Deposition Additive Manufacturing nozzle-extrudate flow

Composites Part B Engineering ◽

10.1016/j.compositesb.2021.108811 ◽

2021 ◽

pp. 108811

Author(s):

Zhaogui Wang ◽

Douglas E. Smith

Keyword(s):

Finite Element ◽

Additive Manufacturing ◽

Polymer Composite ◽

Fiber Orientation ◽

Finite Element Modelling ◽

Coupled Flow ◽

Element Modelling ◽

Orientation Effects ◽

Composite Deposition ◽

Fully Coupled

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Effect of the Rock Stress on the Water Jet Cutting Performance

Rock Mechanics and Rock Engineering ◽

10.1007/s00603-021-02508-w ◽

2021 ◽

Author(s):

Battista Grosso ◽

Valentina Dentoni ◽

Augusto Bortolussi

Keyword(s):

Numerical Models ◽

Step Function ◽

Water Jet ◽

The State ◽

Cutting Performance ◽

Lagrangian Analysis ◽

State Of Stress ◽

Water Jet Cutting ◽

Cutting Rate ◽

Available Technology

AbstractUnderground quarrying is rarely adopted for granite extraction due to the difficulties in the implementation of traditional technologies (drilling and explosive). As alternative to drilling and explosive, the combination of diamond wire and water jet seems to be the most promising available technology. The cutting performance achievable with the water jet technology depends on the operative parameters, the material characteristics and the state of stress within the rock massif. To assess the effect of the state of stress on the cutting rate, laboratory tests have been performed with an oscillating water jet machine on granite samples subjected to a static load. The stress distribution in the layer of rock to be removed has been evaluated by numerical simulation with the FLAC code (Fast Lagrangian Analysis of Continua). The correlation between the results of the cutting tests and the numerical models of the rock samples has been inferred. Starting from a conceptual model, which theoretically describes the relationship between the cutting rate and the stress, a step function was defined that indicates the ranges of stress where predefined values of the cutting rate are workable.

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