scholarly journals Fracture energy of columnar freshwater ice: Influence of loading type, loading rate and size

Materialia ◽  
2021 ◽  
Vol 20 ◽  
pp. 101188
Author(s):  
I.E. Gharamti ◽  
J.P. Dempsey ◽  
A. Polojärvi ◽  
J. Tuhkuri
Keyword(s):  
Fracture Energy ◽  
Loading Rate ◽  
Freshwater Ice ◽  
Loading Type

FRACTURE BEHAVIOR OF Zr-BASED BULK METALLIC GLASS UNDER IMPACT LOADING

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4359-4364 ◽  
Author(s):  
HYUNG-SEOP SHIN ◽  
KI-HYUN KIM ◽  
SANG-YEOB OH
Keyword(s):  
Fracture Toughness ◽  
Crack Initiation ◽  
Fracture Energy ◽  
Impact Loading ◽  
Static Loading ◽  
Fracture Behavior ◽  
Loading Rate ◽  
Shear Bands ◽  
Maximum Load ◽  
Cu Alloy

The fracture behavior of a Zr -based bulk amorphous metal under impact loading using subsize V-shaped Charpy specimens was investigated. Influences of loading rate on the fracture behavior of amorphous Zr - Al - Ni - Cu alloy were examined. As a result, the maximum load and absorbed fracture energy under impact loading were lower than those under quasi-static loading. A large part of the absorbed fracture energy in the Zr -based BMG was consumed in the process for crack initiation and not for crack propagation. In addition, fractographic characteristics of BMGs, especially the initiation and development of shear bands at the notch tip were investigated. Fractured surfaces under impact loading are smoother than those under quasi-static loading. The absorbed fracture energy appeared differently depending on the appearance of the shear bands developed. It can be found that the fracture energy and fracture toughness of Zr -based BMG are closely related with the extent of shear bands developed during fracture.

scholarly journals Adfreezing strength of ice to model piles

1987 ◽  
Vol 24 (3) ◽  
pp. 446-452 ◽  
Author(s):  
V. R. Parameswaran
Keyword(s):  
Key Words ◽  
Surface Coating ◽  
Loading Rate ◽  
Surface Characteristics ◽  
Surface Coatings ◽  
Displacement Rate ◽  
Rate Model ◽  
Freshwater Ice

Results of tests to determine the adfreezing strength of freshwater ice to piles having different surface characteristics show that adfreeze strength increases with increase in the rate of displacement and loading of the pile. Surface coatings such as creosote on wood piles and paint and silicone sealer on metallic piles drastically decrease the adfreezing strength of ice. Key words: adfreezing strength, displacement rate, ice, loading rate, model piles, surface coating.

Fracture Toughness of Freshwater Ice—Part I: Experimental Technique and Results

1996 ◽  
Vol 118 (2) ◽  
pp. 135-140 ◽  
Author(s):  
L. J. Weber ◽  
W. A. Nixon
Keyword(s):  
Fracture Toughness ◽  
Experimental Technique ◽  
Test Temperature ◽  
Significant Variation ◽  
Loading Rate ◽  
Companion Paper ◽  
Fractographic Analysis ◽  
Linear Elastic ◽  
Freshwater Ice ◽  
Crack Tip Plasticity

Experiments have been performed to determine the effect of loading rate and temperature on the fracture toughness of both granular and S2 columnar freshwater ice. Loading rate was varied from 0.04 to 40.0 kPam s-1, and over this range the fracture toughness was observed to decrease from 201 to 109 kPam. Examination of load—CMOD curves indicate that at a loading rate of 40 kPam s-1, the crack tip plasticity was sufficiently limited that the specimen behavior can be considered linear elastic, thus providing a valid Kq measurement. When test temperature was varied from −5 to −45°C for the S2 columnar ice, no significant variation in toughness was observed. In contrast, for granular ice, a higher toughness (144 kPam) was observed in the −5 to −20°C range than for the S2 columnar ice. However, the toughness of the granular ice at−45°C is not significantly different from that of the S2 columnar ice. A companion paper (Weber and Nixon, 1996) analyzes the results in greater detail comparing them with previous work, and presents a detailed fractographic analysis of the failure surfaces.

Fracture Toughness of Freshwater Ice—Part II: Analysis and Micrography

1996 ◽  
Vol 118 (2) ◽  
pp. 141-147 ◽  
Author(s):  
L. J. Weber ◽  
W. A. Nixon
Keyword(s):  
Fracture Toughness ◽  
Fracture Surface ◽  
Experimental Technique ◽  
Loading Rate ◽  
Process Zone ◽  
Crack Tip ◽  
Simple Method ◽  
Dislocation Activity ◽  
Freshwater Ice

Experiments have been performed to determine the effect of loading rate and temperature on the fracture toughness of freshwater ice. A first paper (Weber and Nixon, 1996) presents the experimental technique and results, while this paper focuses on discussion of the crack tip process zone and fracture surface micrography. A simple method to estimate the size of the process zone will be presented. Also, fracture surface micrography will be used to interpret the results of the temperature experiments by considering evidence of dislocation activity in preferentially oriented grains.

scholarly journals Interfacial Fracture in Fibre-Metal Laminates Based on Glass Fibre Reinforced Polypropylene

1998 ◽  
Vol 7 (4) ◽  
pp. 096369359800700 ◽  
Author(s):  
G. Reyes ◽  
W.J. Cantwell
Keyword(s):  
Maleic Anhydride ◽  
Fracture Energy ◽  
Glass Fibre ◽  
Loading Rate ◽  
Interfacial Fracture ◽  
Fracture Properties ◽  
Glass Fibre Reinforced ◽  
Fibre Metal ◽  
Fibre Metal Laminate ◽  
Excellent Adhesion

This papers examines the interfacial fracture properties of a new fibre-metal laminate based on glass fibre reinforced polypropylene (GFPP). Tests have shown that excellent adhesion between aluminium and GFPP can be achieved by incorporating a maleic-anhydride modified polypropylene interlayer between the composite and aluminium layers. Single cantilever beam tests have shown that the fracture energy of these systems initially increases with loading rate and then decreasing. In spite of this, the fracture energy is extremely high at all rates.

Effect of loading rate on cohesive parameters of the adhesive Araldite 2015

2020 ◽  
Vol 62 (9) ◽  
pp. 943-950
Author(s):  
Engin Erbayrak ◽  
Halil Ozer
Keyword(s):  
Fracture Toughness ◽  
Plastic Deformation ◽  
Fracture Energy ◽  
Transition Region ◽  
Cantilever Beam ◽  
Epoxy Matrix ◽  
Loading Rate ◽  
Double Cantilever Beam ◽  
Loading Rates ◽  
Softening Behavior

Abstract This study addresses the effect of loading rates on cohesive parameters and microstructural composition of the Araldite 2015 adhesive. Double Cantilever Beam (DCB) samples were tested under the loading rates of 1, 5, 10, 20, 100 and 200 mm × min-1. The Park-Paulinho-Roeser model (PPR model) was used to get cohesive parameters. In modelling of the softening behavior, inverse analyses were performed using the date obtained from the PPR softening curves. It was seen that the fracture energy and cohesive parameters are decreasing with increasing the loading rate. However, there seems to be a transition region where the fracture energy nearly remains constant. Microstructural analyses were implemented in order to study the effects of the loading rates on the characteristics of the fracture surfaces. It was concluded that the loading rates greatly influence the distribution of micro-voids in the epoxy matrix. Moreover, the presence of voids in epoxy matrix improved the plastic deformation around the crack tip and increased the fracture toughness.

scholarly journals Effect of Loading Rate on the Fracture Behaviour of High-Strength Concrete

2010 ◽  
Vol 24-25 ◽  
pp. 179-185 ◽  
Author(s):  
Gonzalo Ruiz ◽  
X.X. Zhang ◽  
R.C. Yu ◽  
E. Poveda ◽  
R. Porras ◽  
...  
Keyword(s):  
Fracture Energy ◽  
High Strength Concrete ◽  
Loading Rate ◽  
High Strength ◽  
Displacement Rate ◽  
Cohesive Law ◽  
Viscous Term ◽  
Strength Concrete ◽  
Loading Rates ◽  
Static Conditions

This research deals with the sensitivity of eight types of performance-designed high-strength concrete to the loading rate. Variations in the composition of the concrete produce the desired performance, for instance having null shrinkage or being able to be pumped at elevated heights without segregation, but they also produce variations in the fracture properties that are reported in this paper. We performed tests at five loading rates spanning six orders of magnitude in the displacement rate, from 1.74  10-5 mm/s to 17.4 mm/s. Load-displacement curves show that their peak is higher as the displacement rate increases, whereas the corresponding displacement is almost constant. Fracture energy also increases, but only for loading rates higher than 0.01 mm/s. We use a formula based on a cohesive law with a viscous term to study the results. The correlation of the formula to the experimental results is good and it allows us to obtain the theoretical value for the fracture energy under strictly static conditions. In addition, both the fracture energy and the characteristic length of the concretes used in the study diminish as the compressive strength of their aggregates increases.

scholarly journals Flaw Tolerance in a Viscoelastic Strip

2013 ◽  
Vol 80 (4) ◽  
Author(s):  
Lei Chen ◽  
Shaohua Chen ◽  
Huajian Gao
Keyword(s):  
Mechanical Properties ◽  
Fracture Energy ◽  
Crack Growth ◽  
Cohesive Zone ◽  
Loading Rate ◽  
Biological Materials ◽  
Time Dependent ◽  
Center Crack ◽  
Flaw Tolerance ◽  
Viscoelastic Strip

Load-bearing biological materials such as bone, teeth, and nacre have acquired some interesting mechanical properties through evolution, one of which is the tolerance of cracklike flaws incurred during tissue function, growth, repair, and remodeling. While numerous studies in the literature have addressed flaw tolerance in elastic structures, so far there has been little investigation of this issue in time-dependent, viscoelastic systems, in spite of its importance to biological materials. In this paper, we investigate flaw tolerance in a viscoelastic strip under tension and derive the conditions under which a pre-existing center crack, irrespective of its size, will not grow before the material fails under uniform rupture. The analysis is based on the Griffith and cohesive zone models of crack growth in a viscoelastic material, taking into account the effects of the loading rate along with the fracture energy, Young’s modulus, and theoretical strength of material.

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