Since the spring is tensioned in the stick phase and relieved in the subsequent slip phase, the friction pair belt and mass m will always attain a maximum relative speed that is higher than the speed of the belt v. Patterning bubbles by the stickslip motion of the advancing. However, increase the velocity of the system can change the system frequency and decrease the stickslip phenomenon amplitude peak zero. Spiny lobsters stick and slip to make sound nature. Linear slide design criteria bearing pressure bearing pressure is measured in pounds per square inch psi. Frictional force measurement during stickslip motion of a piezoelectric walker article pdf available june 2015 with 390 reads how we measure reads. The decrease of the applied weight on bit or an increase of imposed velocity o. Stick slip occurring where the pdc cutters meet the rock has the potential to create the longest stick and most violent slip periods. Other examples of the stick slip phenomenon include the music that comes from bowed instruments, the noise of car brakes and tires, and the noise of a.
This process is continuously repeated while the objects are sliding. It is calculated by distributing the total load in pounds that the bearing is carrying by the projected area length x width in inches. The drillstring and bha above the motor can enter into a stick slip motion even when the motor is turning the bit at a steady rate. They observed a bamboolike morphology of the scratch track corresponding to the stick slip motion. Stickslip can also be observed on the atomic scale using a friction force microscope. Friction fluctuations and friction memory in stickslip motion. Origin of stickslip motion in boundary lubrication science. Stick slip displacement of con ned granular mixtures. At the beginning of the experiment, the slider experiences regular stickslip oscillations with 35 m amplitude and 300 s waiting time figure 2b. Simulating twodimensional stickslip motion of a rigid. Stickslip reduce risk in drilling oil and gas wells. A puzzling phenomenon of icestream flow is the stickslip motion displayed by whillans.
This model shows a mechanical rotational system with stick slip friction. Fs is the necessary condition for existence of stickslip. Tribological properties can be influenced by lubricants like bonded coatings, greases, and fluids. Controlling stickslip noise generation with lubricants tribological contact between plastic or polymer materials can exhibit stick slip behavior that generates noise. A polymer is pressed on a plate which can be made of steel or a polymer which makes an oscillating movement. Modeling and simulation of the self excited stickslip system using bondsim tools 55 this investigation tends to find out if it is possible to limit the maximal amplitude with external excitation. Mechanical models of friction that exhibit hysteresis, stickslip, and the stribeck e. In the slip phase, there is finite relative motion. Supporting information direct observation of single. The mean braking force is where t is the stick slip cycle period. Similar to bowedstringed instruments, such as the violin benade, 1990, the stickslip mechanism in spiny lobsters can be modelled as a mass suspended between two springs. Stickslip motion is the basis for the description of a great variety of phenomena characterized by the presence of sliding friction between bodies with elastic features. Mechanical models of friction that exhibit hysteresis. They observed a bamboolike morphology of the scratch track corresponding to the stickslip motion.
One interesting example of stick slip friction is found in the soundproducing apparatus of many spiny lobster species palinuridae. A complex systems analysis of stickslip dynamics of a. Identification and quantification of stickslip induced. In practice this stickslip motion may repeat until the rotor and pad reach some steadysliding state, or stick and even halt the vehicle. Pdf the occurrence of stickslip phenomenon researchgate. Stay connected with the gmc remote monitoring system. When amplitude of excitation frequency equals zero u00 n, the stationary system is out of equilibrium because of friction force action. Experimental and numerical investigation of effect of stick. External damping can prevent stickslip motion, and both deformative and adhesive frictional.
Consequently, stick slip initiated at the rockcutting interface is highly feared, and is responsible for most downhole tool and tool joint overload failures in the industry. Zhang1,2 1complex and intelligent system laboratory, school of mechanical and power engineering, east china university of science and technology, shanghai, china. Slip process of stickslip motion in the scratching of a. Mechanical rotational system with stickslip motion matlab. Stick slip is generally a dynamic cyclic process where two mating surfaces oscillate between a stick phase and a slip phase. Investigate stick slip intervals with one equation of motion and analyse the effect of the friction noise ammar. One of the major difficulties in modeling stick slip stems from the inaccurate description of some involved parameters and downhole boundary conditions.
Frictional force measurement during stickslip motion of a. The acoustic movements of the spiny lobsters plectrum over the file are generated by stick slip friction between the two surfaces. Stickslip, also referred to as stiction, is the bane of engineers and machine builders who need smooth, precise motion. Drillstring vibrations and vibration modeling product sheet. Friction, and in particular stick slip friction, occurs on every length scale, from the movement of atomic force microscope tips at the nanoscale to the movement of tectonic plates of the earths. Stick slip refers to the fast movement that occurs between two sides of a fault when the two sides of the fault become unstuck.
The breakdown of the noslip condition at fluidsolid interfaces generates a host of interesting fluiddynamical phenomena. In such case, the phenomenon can be interpreted using the tomlinson model. Levent demirel and steve granick materials research laboratory, university of illinois, urbana, illinois 61801 received 4 january 1996 we demonstrate that friction is not always an exact number. A theoretical investigation of frictioninduced selfexcited oscillations for systems with one degree of freedom is proposed. Timeresolved studies of stickslip friction in sheared. Transition from smooth sliding to stickslip motion in a. Bit bounce stick slip bending axial torsional lateral fast slow. To highlight the severity of stick slip, an example of the worst stick slip case seen was a 24 second bit stall and a 1. The mean braking force is where t is the stickslip cycle period. The dynamic analysis of stickslip motion sciencedirect. At larger v, the motion becomes smoother and is affected by the inertia of the upper plate bounding the layer. Mar 18, 2017 video of simple stick slip motion in sliderblock model.
Mechanical rotational system with stickslip motion. Transition from smooth sliding to stickslip motion in a single. Stick slip motion and high speed ejection in granular avalanches detected through a multi sensors flume. Compact precision linear actuators stages with several types. A numerical model for halting events in stick slip motion is also presented. Stickslip vibrations caused by friction interactions between sliding surfaces cause of all sliding noise. Walker,1 antoinette tordesillas,1,a michael small,2 robert p. Car drivers making their tires squeal by abruptly changing speed or direction unknowingly make use of the stick slip effect. Minirod stickslip motors piezo inertia motors are based on a small piezo element moving along a rod when driven with a quasi sawtooth signal. Using a finite element model, this paper investigates the stickslip behavior of a drill string subjected to both deterministic excitation and random excitation. We will also take a perspective gleaned from stick slip theory and show how the insights gained can be deployed to explain fundamental questions concerning the origin, mechanism, and characteristics of flow localization in metallic glasses. May 10, 2001 the lobster plectrum and file suggest a frictional mechanism 3 that is analogous to the stickandslip. To avoid the stickslip motion the system frequency should be far from its natural frequency. A stick phase slow enough to transfer motion, is followed by a very rapid slip phase where the piezo element retracts but the load cannot follow.
Controlling stick slip noise generation with lubricants tribological contact between plastic or polymer materials can exhibit stick slip behavior that generates noise. Figure 9a reveals the friction force behavior for the values of fig. The westermo and udwadia 2 model addresses onedimensional motion and cannot be directly applied to two dimensions, where the frictional effects can be highly nonlinear, particularly when the friction force is distributed to each principal direction. The pdf of the stickslip response in the phase plane is also obtained.
These results indicate that the origin of stick slip motion is thermodynamic instability of the sliding state, rather than a dynamic instability as usually assumed. On the role of fluids in stickslip dynamics of saturated. Pdf stickslip vibrations induced by alternate friction models. Finally, we present a detailed analysis showing distribu.
When the rock snaps back into an unstrained position it is called elastic rebound. Microrobot stickslip motion is accurately captured in simulation. When the shear rate exceeds a critical velocity, the stick slip motion disappears and the friction fluctuates gently around a smaller value. This initial slip of the rotor excites vibration in the driveline and brake subsystems, allowing a condition where the rotor and pad may stick again. How to measure, prevent, and eliminate stickslip and. Pdf the modern concept of seismic processes relays mainly on the model of frictional instability, which develops on the preexisting tectonic. Stick slip motion involves periodic shearmelting transitions and recrystllization of the film. Stickslip vibrations induced by alternate friction models. Bengisu general motors corporation, gm technical center, warren, michigan 48090 adnan akay mechanical engineering department, carnegie mellon university, pittsburgh, pennsylvania 152. Stick slip is responsible for the jerky motion of windshield wipers as well as the squeaking sounds of a loose drive belt. The acoustic movements of the spiny lobsters plectrum over the file are generated by stickslip friction between the two surfaces. A joint was formed during the stick stage and during slip a stem was made. Custom linear slide design criteria durabond slide. Stickslip occurring where the pdc cutters meet the rock has the potential to create the longest stick and most violent slip periods.
If instead of stick slip motion the brake remained at rest at the equilibrium position then. Dynamic model of an oilwell drillstring with stickslip. Investigate stickslip intervals with one equation of motion and analyse the effect of the friction noise ammar a. Stick slip is also experienced in lathes, mill centres, and other machinery where something slides on a slideway. On the hydrodynamics of slipstick spheres journal of.
Figure 1 shows stick slip oscillations in a pcp used for dewatering a coalbed methane well in wyoming. When the static frictional force is nonzero, the friction generally displays two different regimes. Mechanical models of friction that exhibit hysteresis, stick. I attached a motion detector to the plectrum and used. The most widely accepted cause of stickslip motion is that the static. Simply put, its the jerkiness that can plague both plain and recirculating linear bearings when they transition from standstill to motion. The stick slip whirl model was a simplification of drilling confined in a borehole with drilling. Stick slip motion occurred at the mean velocity of 0. Figures 9a and 9b show how repeated velocity variations from zero to about 0. Velocity trends of the microrobot on a silicon surface as a function of magnetic field oscillation.
The rock becomes distorted, or bent, but holds its position until the earthquake occurs. To the unaided eye the motion of sliding objects appears steady. Figure 2a plots the continuous variation in slip of a salt slider against glass, from stickslip to stable sliding over several hundreds of deformation cycles. Driving forces are assigned with two functions,one appropriate for comparison with the test and the other to study stick slip orbits, which have been found to have various types of motion depending on the controlling brake actuation parameters. Patterning bubbles by the stick slip motion of the advancing triple phase line on nanostructures. Dynamic modeling of stick slip motion in an untethered. Dec 01, 2016 stickslip, also referred to as stiction, is the bane of engineers and machine builders who need smooth, precise motion. Both the chain length and stiffness in the amorphous phase the blue chain in the amorphous phase will affect the mechanical properties of the crystal phase especially by affecting the stickslip motion of the polymer chain in the crystal phase, and eventually the whole polymer materials. Controlling stickslip noise generation with lubricants. One interesting example of stickslip friction is found in the soundproducing apparatus of many spiny lobster species palinuridae. We will compile recent progress in studying the dynamics of shearband propagation from serrated flow curves.
The tape is modeled as an axially moving, tensioned, viscoelastic eulerbernoulli beam subjected to boundary disturbances arising from supply and takeup pack runout and stick slip friction between tape and roller surface. Another, more common example which produces sound using stickslip friction is the grasshopper. Physik instrumente usa precision motion control 3,826 views. Analytical investigation of stickslip motions in coupled. Nonlinear modeling for a class of nanorobotic systems. Tse4 1department of mathematics and statistics, university of melbourne, parkville vic 3010 australia 2school of mathematics and statistics, university of western australia, crawley wa 6009, australia. We solve the elastic problem for a steadystate motion of a periodic stick slip pattern and derive equations of motion for the tip and resticking end of the slip pulses. In this paper, we consider such a scenario by investigating the lowreynoldsnumber hydrodynamics of a novel slipstick spherical particle whose surface is partitioned into slip and noslip regions. The friction force is assumed as an odd function of the relative sliding velocity with a jump discontinuity at a value of zero for the relative sliding velocity. In the chart, motor torque varies from 25 to 55 ftlb, which translates after gearing to. A complex systems analysis of stickslip dynamics of a laboratory fault david m. The friction element has a difference between the breakaway and the coulomb frictions, resulting in stick slip motion of the inertia.
The friction characteristic is approximated with a piecewise linear function, i. Uniform motion occurs at high velocities where the film no longer has time to order. A numerical model is developed to study stick slip friction between the roller surface and the tape that travels over it. Slideway oils typically list prevention of stick slip as one of their features. If instead of stickslip motion the brake remained at rest at the equilibrium position then. Dynamic model of an oilwell drillstring with stickslip and bitbounce interaction. Gresham contributing editor people dont often talk about stickslip in every day conversation, even among us tribologically oriented folks. Compact precision linear actuators stages with several. Experiments have shown that, for different molecules, the stick slip motion behavior function of relative velocity in a single is also different. In our laboratory experiments, we describe this jerky type of motion as stick slip. Walker, cryospheric sciences, nasa gsfc, university of maryland sophie nowicki, cryospheric sciences, nasa gsfc modeling of transient flow variations like stick slip events allows inference of physical properties. Furthermore, there is the additional complication that the equations. This gives the average pressure, psi, that the bearing must support. The motion is governed by a static friction force in the stick phase and a velocity dependent kinetic friction force in the slip phase.
Friction fluctuations and friction memory in stick slip motion a. Model slider mass m against countersurface stiffness k of slider support normal force w friction force w, with negative slope physical model and bond graph w m vf. Thus braking effectiveness is reduced by stickslip selfexcited oscillation. Mechanical models of friction that exhibit hysteresis, stick slip, and the stribeck e. Stick slip in seismicallyactive faults is discussed as one.
Stickslip motion of moving contact line on chemically patterned surfaces congminwu1,siulonglei1,tiezhengqian2. One animal that produces sound using stickslip friction is the spiny lobster which rubs its antennae over smooth surfaces on its head. The inertia is driven by a velocity source via a stick slip friction element. In the slip regions we use the linear friction law and do not assume any intrinsic instabilities even at small sliding velocities. How to measure, prevent, and eliminate stickslip and noise. In reality this motion is jerky or intermittent because the objects slow during shear periods and accelerate following the shear. A number of theories, most of which have appeared in the engineer ing literature, have been proposed to explain the mechanics of stick slip. The effect of high frequency is to smooth out the discontinuously of the friction. Results from the simulations show distributions of avalanche size following a power law with exponents close to what we get from experiments. Consequently, stickslip initiated at the rockcutting interface is highly feared, and is responsible for most downhole tool and tool joint overload failures in the industry.
Stickslip motion of moving contact line on chemically. The stick slip motion is almost periodic for spherical particles over a wide range of parameters, whereas it becomes irregular when k is large and v is relatively small. Dynamic model of an oilwell drillstring with stickslip and. The acoustic mechanics of stickslip friction in the. An inertia is connected to a fixed point by spring and damper. Xyz miniature positioning stage with piezo inertia stick slip motor q motion by. Measurements of stick slip and static friction ziegler stick slip test rig to examine lubricants according to their stick slip behaviour, the stick slip test rig ssp from ziegler instruments is used. Pdf dynamics of stickslip motion, whillans ice stream. Stickslip dynamics and recent insights into shear banding in. Stickslip behaviors in both deterministic and random cases are obtained through simulation and compared.
Manipulating different drilling parameters as increasing the rotary speed, decreasing the weight on bit wob or modifiying the drilling mud characteristics as shown in the field to suppress stick and slip motion p. Dynamics of stick slip motion, whillans ice stream, antarctica. Stick slip mitigation plan to improve drilling onepetro. The dynamic interplay between static and sliding friction is fundamental to many animal movements.
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