The Friction Between Car Tires and Decks Under Ship Motions

2006 ◽  
Vol 43 (01) ◽  
pp. 27-39
Author(s):  
Junbo Jia ◽  
Anders Ulfvarson
Keyword(s):  
Friction Coefficient ◽  
Ship Motions ◽  
Pitch Period ◽  
Vertical Location ◽  
Safety Consideration ◽  
Parametric Studies ◽  
The Cost ◽  
Time Of Operation

For roll-on/roll-off (RO/RO) ships, when transporting more cars within the same deck area on board, it is necessary to adjust or take away the current lashing system. Furthermore, this operation may also decrease the cost and time of operation as well as cargo damages due to lashing. This requirement, combined with the safety consideration on cargo shifting, may lead to concepts of lashing-free deck design. One of the lashing-free concepts suggests that in some conditions cars can be secured without using lashings, mainly depending on the friction between the tire and the deck without lashings. By doing a series of parametric studies of vehicle securing without lashings under roll and pitch motions, it was found that the value of the maximum required friction coefficient between the tires and the deck is highly relevant to the roll and pitch amplitude, pitch period, orientation of vehicles on decks, and the vertical location of vehicles from the baseline of the vessel.

Study of Friction Coefficient and Friction Force on Magnetic Abrasive Finishing

2011 ◽  
Vol 675-677 ◽  
pp. 663-666
Author(s):  
Yan Chen ◽  
Akira Shimamoto ◽  
X. Gao ◽  
M.M. Zhang
Keyword(s):  
Friction Coefficient ◽  
Friction Force ◽  
Magnetic Particles ◽  
Good Effect ◽  
Magnetic Abrasive Finishing ◽  
Abrasive Particles ◽  
Abrasive Finishing ◽  
Alumina Particles ◽  
The Cost ◽  
Grinding Efficiency

In order to enhance grinding efficiency of the magnetic abrasive finishing (MAF) method, we usually use the sinter method or the cementation method to mix the magnetic particles and abrasive particles together. However, the cost is high, and the variety is incomplete. Therefore, with the ferromagnetism to iron particles, the alumina particles and the lipin three kind of material simple mixture participate in the magnetic abrasive finishing which directly polishes, already obtained the good effect through the experiment. This paper analyses and explains the characteristic of the friction coefficient and the friction force on magnetic abrasive finishing according as account and experiment data.

scholarly journals Combined Tillage Tools– A Review

2016 ◽  
Vol 4 (2) ◽  
pp. 179-185 ◽  
Author(s):  
Manjeet Prem ◽  
Raghunandan Swarnkar ◽  
Vyas Kantilal ◽  
Pargi Jeetsinh ◽  
Khodifad Chitharbhai
Keyword(s):  
Critical Role ◽  
Conventional Tillage ◽  
Considerable Saving ◽  
Tillage Practices ◽  
Tillage Operation ◽  
Cost Efficient ◽  
Seedbed Preparation ◽  
The Cost ◽  
Time Of Operation ◽  
Number Of Passes

The costliness of energy, forces the farmers to choose another cost efficient tillage methods. The cost as well as time of operation plays a critical role in choosing another tools for tillage. Combined tillage is the way in which two or more different tillage implements operates at the same time in order to manipulate the soil and reduce the number and time of field operations. It was envisaged that such an implement would affect considerable saving of time, fuel and energy. This would also reduce the cost of operation. There was an efficient and potential reduction in the soil compaction, labour and fuel cost, saving in time and reduction of multiple tillage operation in single pass. The conventional tillage practices are becoming increasingly expensive in terms of time, fuel and equipment costs and are also causing more soil damage and compaction due to higher number of passes required for the conventional implements during seedbed preparation. As the land sizes in India are small, the scope for increasing the speed or width of existing implements is less feasible. Hence, reducing the number of passes by combining two or more field operations with the use of combination tillage implements may provide better solution. In a single run the combined tillage tool performs primary as well as secondary tillage operations.

scholarly journals Analytical bond behavior of cold drawn SMA crimped fibers considering embedded length and fiber wave depth

2021 ◽  
Vol 60 (1) ◽  
pp. 862-883
Author(s):  
Ha Vinh Ho ◽  
Eunsoo Choi ◽  
Jun Won Kang
Keyword(s):  
Finite Element ◽  
Friction Coefficient ◽  
Fiber Reinforced Concrete ◽  
Recovery Stress ◽  
Bond Behavior ◽  
Fea Model ◽  
Niti Sma ◽  
Increasing Trend ◽  
Cohesive Surface ◽  
The Cost

Abstract The NiTi SMA fibers were cold drawn to introduce prestrain, and then, they were made to crimped fibers with various wave depths. The recovery stress was measured, which was useful for closing the cracks in fiber-reinforced concrete. The pullout behaviors were also examined considering the existing recovery stress, and it is found that the recovery stress did not influence so much on the pullout behavior. According to the pullout results, a parametric study used a finite element analyzing (FEA) model to quantify the cohesive surface model’s parameters and the value of the friction coefficient. Then, the developed model is used to investigate the crimped fiber’s pullout behavior with various embedded lengths and wave depths. When the fiber in the elastic range, the peak stresses significantly raise due to increasing embedded waves; they show a linear relationship. After the yield of the SMA fiber, the peak stresses are also a function of embedded waves; however, the increasing trend is slow down. Concerning the cost, the even distribution of the fiber, and for guaranteeing the fiber experiences the pulling out, it is recommended that the embedded lengths and corresponding wave depths should be designed to avoid the yield.

scholarly journals Editorial Special Issue: PHM for Railway Systems and Mass Transportation

2020 ◽  
Vol 8 (3) ◽  
Author(s):  
John Andrews ◽  
Thomas B¨ohm ◽  
Pierre Dersin ◽  
J¨orn C. Groos ◽  
Ren´e Schenkendorf
Keyword(s):  
Life Cycles ◽  
Rolling Stock ◽  
Mass Transportation ◽  
Capital Investments ◽  
Cost Drivers ◽  
Railway Systems ◽  
Editorial Special Issue ◽  
Long Time ◽  
The Cost ◽  
Time Of Operation

The railway and mass transportation system is composed of industrial goods with substantial capital investments and long life cycles. This applies to rolling stock like trains, locomotives,wagons, and even more to the infrastructure like signaling, catenary, tracks, bridges, and tunnels. The lifespan of rolling stock is 30 to 40 years while the infrastructure is used 30 to 60 years even more than 100 years in case of tunnels and bridges. As in other industrial goods, the cost drivers are determined in the early design phases but realized mainly during a long time of operation. Maintenance is one of the main cost drivers but essential to a reliable, capable, and – above all – safe operation.

A Novel Activated Carbon Enabled Steam Generation System Under Simulated Solar Light

2018 ◽  
Author(s):  
Ashreet Mishra ◽  
A. G. Agwu Nnanna
Keyword(s):  
Activated Carbon ◽  
Metallic Nanoparticles ◽  
Solar Light ◽  
Bulk Temperature ◽  
Steam Generation ◽  
Simulated Solar Light ◽  
Parametric Studies ◽  
Rate Of Evaporation ◽  
The Cost ◽  
First Time

A number of studies on CNT, Au and Ag solar enabled steam generation with potential application in water purification, distillation and sterilization of medical equipment. The key challenge with these nanoparticles is cost of production hence limiting its wide application for clean water production. This work for the first time, reports on activated carbon enabled steam generation hence addressing the cost limitations of metallic nanoparticles. Activated carbon has high solar absorptivity at various wavelengths of visible light under low concentration. Experiments were carried out using activated carbon and CNT nanofluids and polyurethane membrane with immobilized activated carbon and CNT. A simulated solar light of 1 KW ∼1 Sun was used. The rate of evaporation, temporal and spatial evolution of bulk temperature in the water were monitored automatically and recorded for further data reductions. Parametric studies of the effect of nanoparticle concentration, water quality and salinity were performed. Experimental evidence showed that activated carbon has potential. We reported for the first time that optimal activated carbon concentration for maximum steam generation is 60 % vol. We also obtained a 160 % increase in steam production rate at 60 % concentration of activated carbon when compared with D.I water.

Practical Modeling for Articulated Risers and Loading Columns

1984 ◽  
Vol 106 (4) ◽  
pp. 444-450 ◽  
Author(s):  
J. F. McNamara ◽  
M. Lane
Keyword(s):  
Ship Motions ◽  
Random Waves ◽  
Efficient Design ◽  
Time Step ◽  
Design Studies ◽  
Large Rotations ◽  
Parametric Studies ◽  
Element Approach ◽  
Large Time Step ◽  
Nonlinear Static

An efficient method for the analysis of the linear and nonlinear static and dynamic motions of offshore systems such as risers and single-leg mooring towers is presented. The technique is based on the finite element approach using connected coordinates for arbitrary large rotations and includes terms due to loads such as buoyancy, gravity, random waves, currents, ship motions and Morison’s equation. Practical features include the addition of intermediate articulations and modeling of the loading arm between the riser and associated tanker. Parametric studies are presented to show that stable and accurate results are obtained using relatively large time step increments leading to efficient design studies.

Tribological Behavior of a Flat or Circular Stamp Sliding on Piezoelectric/Piezomagnetic Composites

2017 ◽  
Vol 09 (02) ◽  
pp. 1750018 ◽  
Author(s):  
Yue-Ting Zhou ◽  
Sheng-Jie Pang ◽  
Zheng Zhong
Keyword(s):  
Friction Coefficient ◽  
Integral Equations ◽  
Characteristic Equation ◽  
Single Phase ◽  
Volume Fraction ◽  
Tribological Behavior ◽  
Sliding Contact ◽  
Contact Model ◽  
Parametric Studies ◽  
Stated Problem

A frictional sliding contact model is established for the anisotropic piezoelectric/piezomagnetic composites indented by a flat or circular stamp. The characteristic equation related to monoclinic anisotropic piezoelectric/piezomagnetic composites is of tenth-order. The stated problem is reduced to integral equations whose kernels present an unconventional singularity. Parametric studies reveal that both the volume fraction of the composites and the friction coefficient could significantly affect the tribological behaviors. Numerical results show that the surface quantities have a singularity or spike at the stamp edge, and that the magneto-electro coupling in piezoelectric/piezomagnetic composites does not exist in any single phase.

Modified Laparoscopic Tool for Enhanced Haptic Feedback

2018 ◽  
Author(s):  
Rajesh Kumar ◽  
Sudipto Mukherjee
Keyword(s):  
Friction Coefficient ◽  
Surface Finish ◽  
Haptic Feedback ◽  
Minimal Invasive ◽  
Tactile Sensation ◽  
New Device ◽  
Input Force ◽  
Joint Clearances ◽  
The Cost ◽  
Original Device

Laparoscopic Devices are known to be used in Minimal Invasive Surgeries. However, the devices are unable to transmit the spectrum of feedback of the tissue to the hands of the surgeon, which makes the surgical procedure difficult. We have demonstrated a parameterization for the loss in feedback due to backlash and friction. Backlash is correlated to the joint clearances while friction correlates to joint clearance as well as the surface finish of mating pairs, though joint clearances don’t affect the friction coefficient largely. The laparoscope behavior has been dynamically modeled to understand and predict the behavior. Also, the cost to manufacture the graspers has been weighed against force bandwidth and reliability of improving the joint tolerances of the device so that it is able to transmit the desired force bandwidth. We conclude that to achieve kHz force bandwidth through purely mechanical means would entail prohibitively expensive manufacturing means and hence, we propose an alternate design. The alternate design makes the system deterministic without uncertainty in the position of the joint pins. The kinematically constrained joints in the new device completely transmit the input force spectrum at frequencies of multiple kHz. The non-sophisticated alteration in the original device doesn’t significantly alleviate the cost and eludes the loss of tactile sensation.

Dynamic Frictions between AISI 316L and 3MTM TrizactTM Structured Abrasive Belts during Mirror-Like Polishing

2015 ◽  
Vol 642 ◽  
pp. 227-230
Author(s):  
Bo Sung Yang ◽  
Jin Cheng Yeh ◽  
Ming Shin Tsai ◽  
Jing Lun Liao ◽  
Shun Yi Wu ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Friction Coefficient ◽  
Rotational Speed ◽  
Tangential Velocity ◽  
Dynamic Friction ◽  
Aisi 316L ◽  
Abrasive Machining ◽  
Dynamic Friction Coefficient ◽  
The Press ◽  
The Cost

polishing is an essential process for deriving of the mirror-like surface of the AISI 316L stainless steel to minimize the surface roughness. Sliding, plowing and cutting, the fundamental mechanisms of abrasive machining, are occurred during the polishing and then would decrease the roughness on the surface. By 3MTM TrizactTM structured abrasive belts, the previous stainless steel are polished. Pyramid arrays containing the abrasives and epoxy formed on the belt give the abrasive machining. The glass transition and degradation temperatures of epoxy are about 150 and 250 degrees, respectively. The friction coefficient between the AISI 316L workpiece and 3MTM TrizactTM structured abrasive belt under different rotational speed may affect the polishing efficiency and the cost. The mechanism of the abrasive machining includes the sliding, plowing and cutting while the previous two are preferred during polishing. By 3MTM TrizactTM Structured Abrasive belts, the grit sizes are #800 and #2000, the MIM stainless steel cases are polished. The contact dynamic friction coefficient induces a higher specific polishing energy, the polishing temperature is thus increased. Deriving the friction coefficient is therefore important for stainless steel polishing. Experimental results indicate that the dynamic friction coefficient decreases respect to the rotational speed and the press-on force of workpiece. The coefficients of friction of all the workpieces under different tangential velocity are in a large range of 1.2–5.6, but the friction coefficient of the tangential velocity of 23.56 m/sec shows slightly variation even press-on force in 5 Newtons or in 20 Newtons.

scholarly journals Evaluation of an Improved Technique for Geosynthetic-Reinforced and Pile-Supported Embankment

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jun Zhang ◽  
Shao-wen Liu ◽  
He-fu Pu
Keyword(s):  
Elastic Modulus ◽  
Conventional Technique ◽  
Cost Evaluation ◽  
Effective Measure ◽  
Parametric Studies ◽  
The Stability ◽  
Improved Technique ◽  
The Cost ◽  
Grps Embankment ◽  
Pile Supported Embankment

With a large number of applications of conventional technique for geosynthetic-reinforced and pile-supported (GRPS) embankment (called CT embankment), many deficiencies have been exposed. In view of the deficiencies, an improved technique, fixed-geosynthetic-reinforced and pile-supported embankment (called FGT embankment), is developed. To investigate the performance of the FGT embankment, the comparison analyses and parametric studies are conducted by Finite Element Method (FEM). The influencing factors investigated include elastic modulus of soil, tensile stiffness of geosynthetics, pile length, pile spacing, and pile elastic modulus. In addition, the cost evaluation for the FGT embankment and CT embankment is also made. The results show that the FGT embankment can significantly reduce the settlement and differential settlement, enhance the stability, and provide an economical and effective measure for the construction of high embankment at the bridge approach.

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