Estimation of crack initiation and crack damage stress by means of mechanical, physical and dynamical properties in brecciated marbles

AbstractThe Oort cloud probably is the source of Halley-type (HT) comets and perhaps of some Jupiter-family (JF) comets. The process of capture of Oort cloud comets into HT comets by planetary perturbations and its efficiency are very important problems in comet ary dynamics. A small fraction of comets coming from the Oort cloud − of about 10−2− are found to become HT comets (orbital periods < 200 yr). The steady-state population of HT comets is a complex function of the influx rate of new comets, the probability of capture and their physical lifetimes. From the discovery rate of active HT comets, their total population can be estimated to be of a few hundreds for perihelion distancesq <2 AU. Randomly-oriented LP comets captured into short-period orbits (orbital periods < 20 yr) show dynamical properties that do not match the observed properties of JF comets, in particular the distribution of their orbital inclinations, so Oort cloud comets can be ruled out as a suitable source for most JF comets. The scope of this presentation is to review the capture process of new comets into HT and short-period orbits, including the possibility that some of them may become sungrazers during their dynamical evolution.

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Dynamical properties of highly entangled polyalkylmethacrylate solutions : A comparative study

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:2000765 ◽

2000 ◽

Vol 10 (PR7) ◽

pp. Pr7-321-Pr7-324

Author(s):

V. Villari ◽

A. Faraone, ◽

S. Magazù, ◽

G. Maisano ◽

R. Ponterio

Keyword(s):

Comparative Study ◽

Dynamical Properties

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CRACK INITIATION I N CORROSION FATIGUE AT DEFINED GRAIN BOUNDARIES I N BI- AND POLYCRYSTALS

Le Journal de Physique Colloques ◽

10.1051/jphyscol:19901112 ◽

1990 ◽

Vol 51 (C1) ◽

pp. C1-703-C1-708

Author(s):

J. WALTERSDORF ◽

H. VEHOFF

Keyword(s):

Crack Initiation ◽

Grain Boundaries ◽

Corrosion Fatigue

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Computational studies on the static and dynamical properties of one dimensional integer spin quantum magnets

10.32657/10356/143094 ◽

2020 ◽

Author(s):

◽

Ernest Teng Siang Ong

Keyword(s):

Computational Studies ◽

Quantum Magnets ◽

One Dimensional ◽

Integer Spin ◽

Spin Quantum ◽

Dynamical Properties

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Rubber Fracture Characterization Using J-Integral

Tire Science and Technology ◽

10.2346/1.2148797 ◽

1988 ◽

Vol 16 (1) ◽

pp. 44-60 ◽

Cited By ~ 14

Author(s):

C. L. Chow ◽

J. Wang ◽

P. N. Tse

Keyword(s):

Crack Initiation ◽

Carbon Black ◽

Natural Rubber ◽

Fracture Parameter ◽

J Integral ◽

Specimen Length ◽

Fracture Characterization ◽

Premature Failure ◽

Testing Procedures ◽

Material Evaluation

Abstract The use of the J-integral to investigate fracture characterization in a carbon black reinforced natural rubber is described. Three applications to crack initiation are included: two based on the use of a hypothetical zero specimen length and one on conventional testing procedures for metals. While the validity of the zero-length methods is questionable, the conventional method yielded a consistent Jc value of 1.01 N/mm for a typical tire compound. This value was obtained from 24 combinations of varying specimen geometries and pre-crack lengths. The J-integral is revealed as a valid fracture parameter that is applicable not only for material evaluation but also for designing tire structures to resist premature failure. These conclusions disagree with those from an earlier investigation, so the causes for the discrepancies are examined and discussed.

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Pseudo-Anosov Theory

10.23943/princeton/9780691147949.003.0015 ◽

2017 ◽

Cited By ~ 1

Author(s):

Benson Farb ◽

Dan Margalit

Keyword(s):

Braid Groups ◽

Intersection Numbers ◽

Branched Covers ◽

Algebraic Integers ◽

Dehn Twists ◽

Mapping Classes ◽

Dynamical Properties

This chapter focuses on the construction as well as the algebraic and dynamical properties of pseudo-Anosov homeomorphisms. It first presents five different constructions of pseudo-Anosov mapping classes: branched covers, constructions via Dehn twists, homological criterion, Kra's construction, and a construction for braid groups. It then proves a few fundamental facts concerning stretch factors of pseudo-Anosov homeomorphisms, focusing on the theorem that pseudo-Anosov stretch factors are algebraic integers. It also considers the spectrum of pseudo-Anosov stretch factors, along with the special properties of those measured foliations that are the stable (or unstable) foliations of some pseudo-Anosov homeomorphism. Finally, it describes the orbits of a pseudo-Anosov homeomorphism as well as lengths of curves and intersection numbers under iteration.

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