Ice Loads on Azimuthing Podded Propulsors

2004 ◽  
Author(s):  
Ayhan Akinturk ◽  
Stephen J. Jones ◽  
Dale Duffy ◽  
Barbara Rowell
Keyword(s):  
Shear Strength ◽  
Flexural Strength ◽  
Ice Sheets ◽  
Experimental System ◽  
Experimental Setup ◽  
Propeller Shaft ◽  
Time Intervals ◽  
Ice Loads ◽  
Propulsion Unit ◽  
Initial Results

The paper describes the experimental setup and presents some of the results obtained. The experimental system is designed and built to measure the loads on the blade, on the propeller shaft bearings, on the shaft, and on the whole propulsion unit (global loads). Experiments have been conducted at various headings form 0° to 180°, thrust directions (aft or forward), and advance coefficients. In the experiments, ice sheets of 60 mm thickness were used. Target flexural strength of the ice sheets was 60 kPa at the start of the experiments. During the course of the experiments, thickness, flexural, compressive and shear strength values of the ice sheets were sampled at certain time intervals in order to record the variations in the ice properties. Initial results suggest that there was an increase of the loads exerted on the podded system due to ice. The increase varies at different azimuth angles and advance velocities.

Measuring Ice Loading on Podded Propellers Systems

2003 ◽  
Author(s):  
Ayhan Akıntu¨rk ◽  
Stephen Jones ◽  
Corwyn Moores ◽  
John Bell
Keyword(s):  
Research Council ◽  
International Association ◽  
National Research Council ◽  
Experimental System ◽  
Propeller Shaft ◽  
Propulsion Systems ◽  
Lack Of Information ◽  
Ice Loads ◽  
Arctic Navigation ◽  
Thrust And Torque

Currently, work is ongoing to update all of the regulations governing the design of vessels for arctic navigation including the propulsion systems by the International Association of Classification Societies. However, there is a lack of information as to the loads occurring on podded propeller systems operating in ice. Hence, this study aims to close the knowledge gap for this type of propulsion systems. This paper describes the experimental setup designed and built at the National Research Council of Canada Institute for Marine Dynamics (NRC-IMD), for measuring ice loads on such a system. The experimental system is designed to measure the loads on three levels: 1– loads on an individual blade (six components), 2– loads on the propeller shaft (thrust and torque) and, the fore and aft bearings which support the propeller shaft (six components), 3– global forces and moments on the (propeller + pod + strut) system (six components).

Online-Joining of C/SiC-C/SiC via Slurry Reaction and Precursor Infiltration and Pyrolysis Process with C/SiC Pins

2012 ◽  
Vol 531-532 ◽  
pp. 135-140 ◽  
Author(s):  
Yu Di Zhang ◽  
Hai Feng Hu ◽  
Chang Rui Zhang ◽  
Guang De Li
Keyword(s):  
Shear Strength ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Fracture Mode ◽  
Pyrolysis Process ◽  
Strong Bond ◽  
Sic Composites ◽  
Maximum Shear Strength ◽  
Application Prospects ◽  
Complex Components

C/SiC composites have widely application prospects in the field of aeronautic and aerospace for their excellent properties. The joining of C/SiC composites is a key to fabricate large and complex components. In this paper, 1D C/SiC pins were prepared by precursor infiltration and pyrolysis (PIP) process and used to join C/SiC composites by Slurry react (SR) and PIP process. The shear strength of the C/SiC pins with different carbon fiber volumes was investigated with the maximum shear strength as high as 339.46MPa. Influences of C/SiC pins on the joining properties of C/SiC composites were studied. The shear strength and flexural strength of C/SiC-C/SiC joining are improved from 9.17MPa and 30.41MPa without pins to 20.06MPa and 75.03MPa with one C/SiC pin (diameter 2mm), respectively. The reliability of C/SiC-C/SiC joining is also improved with C/SiC pins in that the fracture mode changes from catastrophic without pins to non-catastrophic. The SEM photos show a strong bond between joining layer and C/SiC composites without obvious interface.

Scale Effect in Ice Flexural Strength

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Mohamed Aly ◽  
Rocky Taylor ◽  
Eleanor Bailey Dudley ◽  
Ian Turnbull
Keyword(s):  
Flexural Strength ◽  
Sea Ice ◽  
Probabilistic Models ◽  
Scale Effects ◽  
Offshore Structures ◽  
Bridge Piers ◽  
Freshwater Ice ◽  
Flexural Failure ◽  
Ice Loads ◽  
Ice Strength

Ice flexural strength is an important parameter in the assessment of ice loads on the hulls of ice-class ships, sloped offshore structures, and sloped bridge piers. While scale effects in compressive ice strength are well known, there has been debate as to the extent of scale effects in ice flexural strength. To investigate scale effects during flexural failure of both freshwater and saline ice, a comprehensive up-to-date database of beam flexural strength measurements has been compiled. The database includes 2073 freshwater ice beam tests with beam volumes between 0.00016 and 2.197 m3, and 2843 sea ice beam tests with volumes between 0.00048 and 59.87 m3. The data show a considerable decrease in flexural strength as the specimen size increases, when examined over a large range of scales. Empirical models of freshwater ice flexural strength as a function of beam volume, and of saline ice as function of beam and brine volumes have been developed using regression analysis. For freshwater ice, the scale-dependent flexural strength is given as: σf=839(V/V1)−0.13 For sea ice, the dependence of flexural strength has been modeled as: σ=1324(V/V1)−0.054e−4.969vb. Probabilistic models based on the empirical data were developed based on an analysis of the residuals, and can be used to enhance probabilistic analysis of ice loads where ice flexural strength is an input.

Scale Effect in Freshwater Ice Flexural Strength

2018 ◽  
Author(s):  
Mohamed Aly ◽  
Rocky Taylor ◽  
Eleanor Bailey Dudley ◽  
Ian Turnbull
Keyword(s):  
Flexural Strength ◽  
Large Range ◽  
Scale Effects ◽  
Offshore Structures ◽  
Bridge Piers ◽  
Considerable Decrease ◽  
Freshwater Ice ◽  
Flexural Failure ◽  
Ice Loads ◽  
Ice Strength

Ice flexural strength is an important parameter in the assessment of ice loads on the hulls of ice-class ships, sloped offshore structures or sloped bridge piers. While scale effects are well known for compressive ice strength, there has been debate as to whether or not scale effects in ice flexural strength exist. To investigate scale effects during flexural failure of freshwater ice, a comprehensive up-to-date database of beam flexural strength measurements has been compiled. The data show a considerable decrease in flexural strength as the specimen size increases, when examined over a large range of scales. An empirical model of freshwater ice flexural strength as a function of beam volume has been developed using regression analysis.

The Research of the Orgince Silicone Emulsion Hybridized Chromium-Aluminum Phosphate Composites

2013 ◽  
Vol 699 ◽  
pp. 519-523
Author(s):  
Da Qing Chen ◽  
Hai Bin Wang ◽  
Ji Chuan Huo ◽  
Yong Lin Lei ◽  
Wei Ai
Keyword(s):  
Shear Strength ◽  
Flexural Strength ◽  
Aluminum Phosphate ◽  
Lap Shear Strength ◽  
Lap Shear ◽  
Silicone Emulsion ◽  
Chromium Phosphate

In the paper ,the preparation of the orgincesilicone emulsion hybridized chromium-aluminum phosphateand thecomposites was studied.The aluminum-chromium-phosphate washybridizedbyadding the orgincesilicone emulsio-n, the tensile lap-shear strength of the hybridized aluminum-chromium-phosphateincreasedfrom1.2MPato4.0MPaor more, its dielectricconstantwasreducedfromabout 4.0toabout3.6; the flexural strength of the composites was increased from80Mpa tomore than120Mpa and the the moisture rate of the composites reduced to about 1.6%

scholarly journals Flexural Strength of Glass Carbomer Cement and Conventional Glass Ionomer Cement Stored in Different Storage Media over Time

2018 ◽  
Vol 27 (4) ◽  
pp. 372-377 ◽  
Author(s):  
Muhammad Ali Faridi ◽  
Abdul Khabeer ◽  
Saad Haroon
Keyword(s):  
Flexural Strength ◽  
Artificial Saliva ◽  
Glass Ionomer Cement ◽  
Bending Test ◽  
Glass Ionomer ◽  
Time Intervals ◽  
Storage Media ◽  
Unique Factor ◽  
Post Hoc ◽  
Ionomer Cement

Objectives: Glass ionomer cement (GIC) is routinely placed as a restorative material in dentistry. However, due to its poor physical properties, its use is limited to cases where the level of stress on restoration is minimal. Improved formulations of GIC have been developed to overcome these drawbacks. The purpose of this study was to evaluate flexural strength of a conventional GIC (Fuji IX) against a newly developed glass carbomer cement (GCP). Materials and Methods: For Fuji IX and GCP, a total of 80 blocks were prepared and divided into 16 groups (n = 5). These groups were further categorized according to the storage medium (artificial saliva and Vaseline) and time intervals (24 h and 1, 2, and 4 weeks). A 3-point bending test was carried out, and statistical analysis was done using ANOVA and Tukey post hoc tests. Results: Fuji IX showed a mean flexural strength of 25.14 ± 13.02 versus 24.27 ± 12.57 MPa for GCP. There was no significant statistical difference between both materials when compared under storage media. Both materials showed the highest value for flexural strength at 2 weeks of storage and lowest at 4 weeks. Conclusion: The storage media do not affect the flexural strength of the specimens with reference to time. Time is the unique factor with relative influence on mean resistance to fracture. Further testing is required to evaluate the true potential of the newly developed GCP.

scholarly journals Effect of Carbon Nanotube Deposition Time to the Surface of Carbon Fibres on Flexural Strength of Resistance Welded Carbon Fibre Reinforced Thermoplastics Using Carbon Nanotube Grafted Carbon Fibre as Heating Element

2019 ◽  
Vol 3 (1) ◽  
pp. 9 ◽  
Author(s):  
Kazuto Tanaka ◽  
Takanobu Nishikawa ◽  
Kazuhiro Aoto ◽  
Tsutao Katayama
Keyword(s):  
Shear Strength ◽  
Carbon Nanotube ◽  
Flexural Strength ◽  
Carbon Fibre ◽  
Deposition Time ◽  
Heating Element ◽  
Resistance Heating ◽  
Carbon Fibres ◽  
Lap Shear ◽  
Reinforced Thermoplastics

In recent years, carbon fibre reinforced thermoplastics (CFRTP) are expected to be used as lightweight structural materials for mass-produced vehicles. CFRTP with thermoplastics as matrix allows us to weld them using melting of matrix by heating. We have been developing a direct resistance heating method, which uses carbon fibres as the resistance heating element. Carbon nanotube (CNT) is expected to be used as additive to FRP and we reported that the fibre/matrix interfacial shear strength was improved by grafting CNT on the surface of carbon fibres and tensile lap-shear strength was improved by using CNT grafted carbon fibre as the heating element for welding. For the practical use of CFRTP for structural parts, flexural strength is also necessary to be evaluated. In this study, flexural test was carried out to clarify the effect of CNT deposition time to the surface of carbon fibres on flexural strength of resistance welded CFRTP using CNT grafted carbon fibre as the heating element. The highest flexural strength was obtained when CNT10, for which CNT is grafted on the carbon fibres for deposition time of 10 min, was used for the heating element of resistance welding. In the case of CNT deposition time of 60 min, the lowest flexural strength was obtained because of the poor impregnation of the resin into the carbon fibre due to the excess CNT on the carbon fibres.

scholarly journals Effect of Graphene Additive on Flexural and Interlaminar Shear Strength Properties of Carbon Fiber-Reinforced Polymer Composite

2020 ◽  
Vol 4 (4) ◽  
pp. 162
Author(s):  
Mohamed Ali Charfi ◽  
Ronan Mathieu ◽  
Jean-François Chatelain ◽  
Claudiane Ouellet-Plamondon ◽  
Gilbert Lebrun
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Interlaminar Shear Strength ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Adhesion Properties ◽  
Reinforced Polymer ◽  
Interlaminar Shear

Composite materials are widely used in various manufacturing fields from aeronautic and aerospace industries to the automotive industry. This is due to their outstanding mechanical properties with respect to their light weight. However, some studies showed that the major flaws of these materials are located at the fiber/matrix interface. Therefore, enhancing matrix adhesion properties could significantly improve the overall material characteristics. This study aims to analyze the effect of graphene particles on the adhesion properties of carbon fiber-reinforced polymer (CFRP) through interlaminar shear strength (ILSS) and flexural testing. Seven modified epoxy resins were prepared with different graphene contents. The CFRP laminates were next manufactured using a method that guarantees a repeatable and consistent fiber volume fraction with a low porosity level. Short beam shear and flexural tests were performed to compare the effect of graphene on the mechanical properties of the different laminates. It was found that 0.25 wt.% of graphene filler enhanced the flexural strength by 5%, whilst the higher concentrations (2 and 3 wt.%) decreased the flexural strength by about 7%. Regarding the ILSS, samples with low concentrations (0.25 and 0.5 wt.%) demonstrated a decent increase. Meanwhile, 3 wt.% slightly decreases the ILSS.

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