scholarly journals Mixed Mode Crack Propagation in Polymers Using a Discrete Lattice Method

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1290
Author(s):  
Matías Braun ◽  
Josué Aranda-Ruiz ◽  
José Fernández-Sáez
Keyword(s):  
Crack Propagation ◽  
Lattice Model ◽  
Nearest Neighbor ◽  
Peak Load ◽  
Polymeric Materials ◽  
Discrete Models ◽  
Lattice Method ◽  
Crack Propagation Process ◽  
Static Fracture ◽  
Selection Of

The fracture behavior of polymeric materials has been widely studied in recent years, both experimentally and numerically. Different numerical approaches have been considered in the study of crack propagation processes, from continuum-based numerical formulations to discrete models, many of the latter being limited in the selection of the Poisson’s coefficient of the considered material. In this work, we present a numerical and experimental analysis of the crack propagation process of polymethylmethacrylate beams with central and eccentric notches subjected to quasi-static three-point bending tests. The developed discrete numerical model consists of a regular triangular lattice model based on axial and normal interaction springs, accounting for nearest-neighbor interactions. The proposed model allows solving the above mentioned limitation in the selection of Poisson’s coefficient, incorporating a fracture criterion defined by a bilinear law with softening that includes the fracture energy in the formulation and allows considering a progressive damage. One of the main objectives of this work is to show the capacity of this lattice to simulate quasi-static fracture problems. The obtained results show that the proposed lattice model is capable of providing results close to the experimental ones in terms of crack pattern, peak load and initial stiffening.

scholarly journals Interfacial Failure in Stitched Foam Sandwich Composites

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2275
Author(s):  
Yue Hu ◽  
Jun Zhu ◽  
Jihui Wang ◽  
Yibo Wu
Keyword(s):  
Crack Propagation ◽  
Strain Energy ◽  
Critical Strain ◽  
Peak Load ◽  
Sandwich Composite ◽  
Displacement Curve ◽  
Release Rates ◽  
Propagation Process ◽  
Crack Propagation Process ◽  
Fracture Tests

In this paper, the use of a customized automatic reinforcement stitching equipment was demonstrated. The stitching of foam sandwich composite preforms was achieved to obtain structures with improved interfacial properties. The effect of different stitching spacings on the crack propagation process in glass fiber reinforced plastics (GFRP)/foam sandwich composite interfaces was examined by Mode-I Cracked Sandwich Beam (CSB) fracture tests. The load–displacement curve, the crack propagation process, and the release rate of critical strain energy were analyzed. The CSB fracture test results show that the stitching treatment with different stitching spacings increase the peak load and fracture displacement. Furthermore, it was found that the mechanism of crack propagation is changed by the stitching process. The release rates of the critical strain energy in specimens with 0- and 10-mm stitch spacings were evenly distributed, with an average of 0.961 kJ/m2 and 1.667 kJ/m2, respectively, while the release rates of critical strain energy in specimens with 6-mm and 8-mm stitch spacings were linearly distributed. The CSB fracture tests confirmed that the best suture spacing was 8 mm. Based on these results, the mechanism of crack propagation and the toughening mechanism of the resin column could be revealed.

Numerical Simulation on the Compound Crack Propagation Process in Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 1139-1142
Author(s):  
Pei Xiu Xia ◽  
Guang Ping Zou ◽  
Li Qiang Tang
Keyword(s):  
Numerical Simulation ◽  
Crack Propagation ◽  
Failure Process ◽  
Peak Load ◽  
Propagation Path ◽  
Propagation Process ◽  
Load Increase ◽  
Crack Propagation Process ◽  
Crack Initiation Angle ◽  
Concrete Materials

In this paper, numerical simulation on the failure process of the mixed mode crack about the concrete is carried out. The results show that the crack initiation angle and the peak load increase as the distance between the preexisting crack and the midline of the beam is greater, the distance is constant, the longer the length of the preexisting crack is, the bigger the peak load is. Due to the heterogeneity of concrete materials, the crack propagation path is tortuous, and tensile stress is the major driving force.

A Case Based Reasoning System For Recommendation Of Restaurant In Jimbaran Using K-Nearest Neighbor

2020 ◽  
Vol 9 (2) ◽  
pp. 267
Author(s):  
I Gede Teguh Mahardika ◽  
I Wayan Supriana
Keyword(s):  
Recommendation System ◽  
Nearest Neighbor ◽  
Case Based Reasoning ◽  
Retrieval Process ◽  
K Nearest Neighbor ◽  
Reasoning System ◽  
Human Ability ◽  
And Function ◽  
Case Based ◽  
Selection Of

Culinary is one of the favorite businesses today. The number of considerations to choose a restaurant or place to visit becomes one of the factors that is difficult to determine the restaurant or place to eat. To get the desired place to eat advice, one needs a recommendation system. Decisions made by the recommendation system can be used as a reference to determine the choice of restaurants. One method that can be used to build a recommendation system is Case Based Reasoning. The Case Based Reasoning (CBR) method mimics human ability to solve a problem or cases. The retrieval process is the most important stage, because at this stage the search for a solution for a new case is carried out. The study used the K-Nearest Neighbor method to find closeness between new cases and case bases. With the selection of features used as domains in the system, the results of recommendations presented can be more suggestive and accurate. The system successfully provides complex recommendations based on the type and type of food entered by the user. Based on blackbox testing, the system has features that can be used and function properly according to the purpose of creating the system.

scholarly journals Simultaneous Selection of Features and Metric for Optimal Nearest Neighbor Classification

2004 ◽  
Vol 33 (9) ◽  
pp. 2137-2157 ◽  
Author(s):  
David A. Johannsen ◽  
Edward J. Wegman ◽  
Jeffrey L. Solka ◽  
Carey E. Priebe
Keyword(s):  
Nearest Neighbor ◽  
Nearest Neighbor Classification ◽  
Simultaneous Selection ◽  
Neighbor Classification ◽  
Selection Of

Analysing sport data with clusters of opposite preferences

2018 ◽  
Vol 18 (5-6) ◽  
pp. 505-524 ◽  
Author(s):  
Rosaria Simone ◽  
Maria Iannario
Keyword(s):  
Sport Participation ◽  
Sport Activity ◽  
Discrete Models ◽  
Component Mixture ◽  
Rating Data ◽  
Self Evaluation ◽  
Specific Policy ◽  
Two Component ◽  
Competing Models ◽  
Selection Of

In the analysis of questionnaire-based evaluation of sport preferences, measurements of sport participation, opinions on social implications such as resurgence of racism, violence in stadiums and doping, the need arises to establish connections among motivations, subjects’ characteristics and responses. In this setting, the article deals with a selection of statistical models suitable to analyse sport rating data in which clusters of opposite responses are observed. Specifically, a two-component mixture of inverse hypergeometric (MIHG) distributions will be introduced and tested against competing models in order to yield a multifold interpretation of results. The ultimate comparative analysis will consider discrete models with a specific focus on those accounting for both uncertainty and feeling of self-evaluation in presence of inflation at the extreme categories. After a brief review of the methods, the proposal will be discussed both on ranking and rating data on the basis of two surveys on sport preferences and on measurements of sport activity: the identification of clusters of respondents with opposite choices will be investigated also in terms of covariates by comparing fitting performances of the selected models. The conclusions and insights offered by the study can be exploited to design plans of action for some specific policy or marketing strategy.

scholarly journals Selection of Pairings Reaching Evenly Across the Data (SPREAD): A simple algorithm to design maximally informative fully crossed mating experiments

2014 ◽  
Author(s):  
Kolea Zimmerman ◽  
Daniel Levitis ◽  
Ethan Addicott ◽  
Anne Pringle
Keyword(s):  
Nearest Neighbor ◽  
Simple Algorithm ◽  
Two Dimensional ◽  
Neighbor Distance ◽  
Crossing Experiments ◽  
The Mean ◽  
Parameter Values ◽  
Selection Of ◽  
Novel Algorithm ◽  
Trait Space

We present a novel algorithm for the design of crossing experiments. The algorithm identifies a set of individuals (a ?crossing-set?) from a larger pool of potential crossing-sets by maximizing the diversity of traits of interest, for example, maximizing the range of genetic and geographic distances between individuals included in the crossing-set. To calculate diversity, we use the mean nearest neighbor distance of crosses plotted in trait space. We implement our algorithm on a real dataset ofNeurospora crassastrains, using the genetic and geographic distances between potential crosses as a two-dimensional trait space. In simulated mating experiments, crossing-sets selected by our algorithm provide better estimates of underlying parameter values than randomly chosen crossing-sets.

Ground states of a ternary fcc lattice model with nearest- and next-nearest-neighbor interactions

1994 ◽  
Vol 49 (1) ◽  
pp. 1-7 ◽  
Author(s):  
G. Ceder ◽  
G. D. Garbulsky ◽  
D. Avis ◽  
K. Fukuda
Keyword(s):  
Lattice Model ◽  
Nearest Neighbor ◽  
Ground States ◽  
Fcc Lattice

The Comparison of Self-Compacting Rock-Filled Concrete with Large-Size Natural and Recycled Aggregate

2014 ◽  
Vol 513-517 ◽  
pp. 20-23
Author(s):  
Hai Chao Wang ◽  
Xue Hua Wang ◽  
Xue Hui An
Keyword(s):  
Fracture Toughness ◽  
Crack Propagation ◽  
Fracture Energy ◽  
Fracture Mechanism ◽  
Recycled Aggregate ◽  
Propagation Process ◽  
Fracture Characteristics ◽  
Three Point Bending ◽  
Large Size ◽  
Crack Propagation Process

The different fracture characteristics of self-compacting rock-filled concrete with large-size natural and recycled aggregate are analyzed by three-point bending experiment. According to the analysis of the crack propagation process, the fracture mechanism differences of self-compacting rock-filled concrete with large-size natural and recycled aggregate are discussed. The further analysis of the differences of fracture toughness, fracture energy, and are gain

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