Science topic

# Friction - Science topic

Friction is a surface resistance to the relative motion of one body against the rubbing, sliding, rolling, or flowing of another with which it is in contact.

Questions related to Friction

what is the effect of grains, grain boundaries and dislocation on frictional coefficient..

Hello,

Please help me plot the streamline and isotherm plots for skin friction/ Nusselt number values for different parameters.

Hertzian contact pressure of the experimental ball-on-disk friction interface

I have a problem of embankment constructed on clay layer over sandy soil. The clay layer of a depth 11m and cu=60kPa, sand soil of a depth 39m and angle of internal friction 35.

I carried out tunnel of 6m in diameter in clay layer at different depth 5,8,10m.

In all cases when carried out only tunnel the settlement value is upward.

I used hardening soil model for clay and sand. I used program PLAXIS 3d in analysis.

Hi folks

I want to know the best way to calculate or find the power consumed to produce a friction stor weld joint.

Thanks in advance

There are different frictions in the ball valve aganist openning torque which are packing friction, seat friction and unballanced forces. I am looking for a sample of torque calculations for a ball valve showing the amount of torque for overcoming these frictions.

As it is noticeable, there are several research projects with regard to using of cavitation and the production of bubbles for friction reduction in ship movements. I want to understand the mechanism thoroughly for this process. Also, how much is it practical for decreasing fuel consumption?

Best regards,

Hossein Pouresmaeil

How we will find skin friction along the with pile in PLAXIS 3D ? how we will extract shear stress values along with the pile from PLAXIS model output? pls answer ASAP

We need to understand the relationship between two dependent variables (Frictional Noise and Coefficient of Friction) and three independent variables (Material Hardness, Surface Roughness, and Sliding Frequency). I need help as to which software to use and how to go about it.

Dear colleagues

I have a question:

In interface shear studies between sand and structures such as geosynthetics or CFRP , how we can calculate or achieve

**initial relative density**for**internal and interface friction angles at critical state?****Based on which ASTM, or through which experiments.**

**Please let me know if you have an answer about this question.**

Thank you for your kind responses.

How can I access information about the effect of friction dampers (Coulomb dry friction) on the dynamic equation of motion? Also the effects of this type of damping on the energy balance equation.

Hello,

I've successfully simulated the closure of a flapper non-return valve as illustrated.

The inlet velocity increases gradually with a specific acceleration.

The following UDF is used to specify the motion of the flapper:

#include "udf.h"

DEFINE_SDOF_PROPERTIES(flappers_motion, sdof_prop, dt, time, dtime)

{

Six_DOF_Object *sdof_obj = NULL;

sdof_prop[SDOF_MASS] = 2.73e-3; /* flapper's submerged weight */

sdof_prop[SDOF_IXX] = 2161.86e-9; /* around the hinge */

sdof_prop[SDOF_IYY] = 367.96e-9;

sdof_prop[SDOF_IZZ] = 2471.27e-9;

real m= sdof_prop[SDOF_MASS];

real L= 0.024479 ;

sdof_prop[SDOF_LOAD_M_X] = 0 ;

sdof_prop[SDOF_LOAD_M_Y] = 0.0;

sdof_prop[SDOF_LOAD_M_Z] = 0.0;

real th_deg = theta * 180 * 7 / 22 ; /* valve opening angle, in degree */

sdof_obj = Get_SDOF_Object(DT_PU_NAME(dt));

if (NULLP(sdof_obj))

{

/* Allocate_SDOF_Object must be called with the same name as the udf */

sdof_obj = Allocate_SDOF_Object(DT_PU_NAME(dt));

SDOFO_1DOF_R_P(sdof_obj) = TRUE; /*1DOF rotation*/

SDOFO_DIR(sdof_obj)[0] = 1.0;

SDOFO_DIR(sdof_obj)[1] = 0.0;

SDOFO_DIR(sdof_obj)[2] = 0.0;

SDOFO_CENTER_ROT(sdof_obj)[0] = 0.0;

SDOFO_CENTER_ROT(sdof_obj)[1] = 0.0;

SDOFO_CENTER_ROT(sdof_obj)[2] = 0.0;

SDOFO_CONS_P(sdof_obj) = TRUE; /* constrained motion */

if (SDOFO_CONS_P(sdof_obj))

{

SDOFO_LOC(sdof_obj) = 0.0;

SDOFO_MIN(sdof_obj) = -0.0349 ; /* min allowable angle */

SDOFO_MAX(sdof_obj) = 1.0471 ; /* max allowable angle */

SDOFO_INIT(sdof_obj) = SDOFO_LOC(sdof_obj);

SDOFO_LOC_N(sdof_obj) = SDOFO_LOC(sdof_obj);

}

}

}

But now I want to simulate the closure of the flapper, taking into account the friction at the flapper's hinge.

I tried to just assign the friction value to "sdof_prop[SDOF_LOAD_M_X]" ,but the flapper started to move backwards (opening) until the flow increases, which is not correct.

So I want to get the value of the hydrodynamic torque of the flapper, and compare it to the friction with some kind of "if statement" that may look like this:

real static_friction= 50;

real kinetic_friction=40;

real hydraulic_torque =??? ;

If (hydraulic_torque<static_friction)

{

sdof_prop[SDOF_LOAD_M_X]=0

}

else

{

sdof_prop[SDOF_LOAD_M_X]=-1*kinetic_friction;

}

BUT THE PROBLEM IS :

I don't know the udf code that can get the actual value of the hydraulic_torque on the flapper to compare it to the friction value.

Your help is highly appreciated.

Thanks a lot in advance.

I have 6 reads each one in a Different day and i need to compare f for all with f of moody chart

I am having trouble detecting a large (~900kDa) protein using SDS page. I think the issue I am having is with the protein not migrating onto the gel for some reason or another. I use 3-8% Tris-Acetate gels and load about ~40-60ug of cell lysate. I run the gel at a constant voltage (100V for 30 minutes and then 150V for 2.5 hours) for roughly 3 hours total.

I do notice that as the run progresses the protein ladder progressively runs slower as the resistance increases. Should I therefore be running the gel at constant current instead of constant voltage?

Any suggestions will be much appreciated.

I am perfoming a simulation to determine the elastic/plastic behavior of a polymer material in abaqus.To simulate the plastic behavior of the material I am using a drukcer prager model. I have performed tensile and compression tests in order to determine the input parameters in abaqus (angle of friction, and hardening data). I have encountered convergence problem when I use the linear model, so I am trying to use the hyperbolic model but I do not know how to calculate the parameters for the hyperbolic model (angle of friction, Init Tension), any guideline in how to do it?

I am trying to find the formulation used by SAP2000 to calculate the shear strength of the material so to compare and extract the friction angle and cohesion? or is there another way to know the latter values? As I do have them in my model but couldn't input them.

Many thanks!

I am modeling dynamic compaction in Abaqus. I model the impact of a tamper on the soil and the job completes successfully, but the result has some problems. The impact happens and after that, the tamper starts moving in the opposite direction and bounces up. I want to know why this happens and how can I solve it?

Parts= soil is defined as a 3D deformable part and the tamper is also a deformable part with high young's modulus and in the interaction module, I define rigid body constraint for that.

Property= sandy soil with low cohesion.

No damping is defined, but I think it does not make a considerable difference in the trend.

Interaction= general contact, hard contact, and frictionless ( I also tried assigning a friction coefficient, but it does not change anything.)

For modeling the impact, I assigned velocity to the reference point of the tamper.

I attach the results.

Would you please help me solve this problem? I really need to figure this out.

If you don't have exactly what i'm looking for i would like to know how the Static friction coeficient for plastic material is changing with an increase of temeprature.

For example we have easily friction coeficient for plastic @ ambienat but is it increasing if we are @ 40°C & 50°C and 60° till 80°C

Thanks

For calculation of pile capacity in mudstone, the end bearing was reduced by 50% by the soil investigation agency in calculations. Should any correction be applied to the skin friction component as well?

hi, can any one send the code for reciprocating wear test, find out the coefficient of friction and wear analysis?

Dear fellow contact mechanicians,

I just stumbled over a problem in analytic mechanics of plane Cattaneo problems in the presence of bulk stress.

It is said that the Ciavarella-Jäger principle for "small enough bulk stress" applies to this problem in the following form:

q(x) = \mu*(p(x; P, beta = 0) - p(x; P - Q/mu, beta)),

where q(x) is the tangential contact traction distribution, p(x) the pressure distribution, P the normal line load, Q the tangential line load, mu the friction coefficient and beta a "rotation angle" proportional to the bulk stress, which I will discuss in a minute.

The second term on the right side in above equation corresponds to a "fictious" normal contact problem of the same contacting bodies under the load (P - Q/mu) and with a relative rotation by beta.

The condition of "small enough bulk stress" is basically that the contact area for this "fictious" problem (which corresponds to the stick region in the actual Cattaneo problem), completely lies within the actual contact area. Moreover, a non-zero value of beta will increase the contact length on one side and decrease it on the other side. So, e.g., for Q = 0 the condition of "moderate bulk stress" is actually that beta = 0, i.e., there is no bulk stress.

Now, we know that tangential contact problems have a loading history. Even the Cattaneo problem has a history: first the normal load is applied, and then an increasing tangential load. However, when beginning to apply the tangential load, Q equals zero, so any (constant) bulk stress will violate the "moderate bulk stress condition".

Or to put it more generally: For any non-zero constant bulk stress, the "moderate bulk stress condition" is violated at the beginning of tangential loading.

Does that change anything about the final contact configuration at the end of the Cattaneo loading?

Or am I missing something?

Thank you very much for your help!

Kind regards,

Emanuel

I am working on landfill in plaxis 3d and i have provided the cover system with diffferent layers as given below

1. Top Soil ( vegetative Cover)

2. Drainage layer

3. Compacted Clay Layer

4. Gas collection layer

To analyse what should be the different properties like cohesion, friction angle , Modulus of elasticity, etc which i should provide to different layers

I'm currently working on ball-on-disk tribological test using different oils.

Is there a direct relation between the coefficient of friction and the lubrication regime of the coupled surfaces?

Is the resulting coefficint of friction related to the materials properties or the lubricant properties? Or both of them?

Thank you to all that would help me.

Hello everyone,

I am conducting reciprocating wear test, and I have a question regarding obtaining coefficient of friction. As a matter of fact, the diagram of Coefficient of friction (COF) against time obtained by software has both negative and positive COF values. However, in most of the papers I have seen so far, only positive value of COF has been plotted against time. So, I was wondering if I should take absolute value of my data and then plot or there is another way to do so?

Examples:

*Journal style*[1] Battal T, Bain C D, Weiss M, Darton R C. Surfactant adsorption and Marangoni flow in liquid jets: Experiments.

*J Colloid Interface Sci***263**(1): 250–260 (2003)

*Book style*[2] Bowden F P, Tabor D.

*Friction and Lubrication of Solids*. Oxford (UK): Oxford University Press, 1950.

*Chapter in book style*[3] Compton K G. Seawater tests. In:

*Handbook on Corrosion Testing and Evaluation*. Ailor W H, Ed. New York: John Wiley and Sons, 1971: 507–514.

*Report and proceeding style*[4] Bassani R, Ciulli E, Manfredi E, Manconi S, Polacco A, Pugliese G. Experimental study on wear and fracture in aeronautical gear transmissions. In: Proceedings of the 8th Biennial Conference on Engineering Systems Design and Analysis, Turin, Italy, 2006: 979–986.

*Patent style*[5] Lenz J R. Compact tribology tester. U.S. Patent 6 817 223, Nov. 2004.

*Thesis style*[6] Qian L M. Studies on preparation and nano-tribological properties of ordered films. Ph.D. Thesis. Beijing (China): Tsinghua University, 1999.

*Web style*[7] Information on http://www.brycoat.com/, 2008.

*Article by DOI style*[8] Slifka M K, Whitton J L. Clinical implications of dysregulated cytokine production.

*J Mol Med*https://doi.org/10.1007/s001090000086 (2000).

*Non-English publication style*[9] Jia W, Zhang Q, Bai Z, Ma S, Yao D, Wang Y. Progress on manufacturing techniques of shaped charge liners.

*Rare Metal Mater Eng***36**(9): 1511–1516 (2007) (in Chinese)

*Standard*[10] US-ASTM. ASTM D974-2014 Standard test method for acid and base number by color-indicator titration. ASTM, 2014.

Thank you in advance!

I am trying to probe force reaction in explict but getting error message. The top plate and bottom plate are assigned as frictional contact with 0.2 friction coefficient. Please suggest what is the mistake. I have attached the screenshots.

Can anyone help to check whether the major head loss calculation for the attached pipeline is correct? Kindly advise. Thanks!

**Inclined uphill portion:**

Length, L= 5.68m

Diameter, D=0.5984m

velocity, v= 17.62 m/s

surface roughness / Diameter, e/D =0.000250668

Re=4.08E+05

friction factor, f =0.0165

Pipeline Inclined angle = 70 deg

So,

Head loss=[ f*(L/D)*(v^2)/(2g) ]

**+**L*sin (70 deg) =6.874042435 m**Straight Horizontal portion:**

Length, L= 9.8m

Diameter, D=0.5984m

velocity, v= 17.62 m/s

surface roughness / Diameter, e/D =0.000250668

Re=4.08E+05

friction factor, f =0.0165

Pipeline Inclined angle = 0 deg

So,

Head loss=[ f*(L/D)*(v^2)/(2g) ] =4.276014958 m

**Inclined downhill portion:**

Length, L= 5.68m

Diameter, D=0.5984m

velocity, v= 17.62 m/s

surface roughness / Diameter, e/D =0.000250668

Re=4.08E+05

friction factor, f =0.0165

Pipeline Inclined angle = 70 deg

So,

Head loss= [ f*(L/D)*(v^2)/(2g) ]

**-**Lsin (70 deg) = -1.917355708mTotal head loss= 6.874042435 m + 4.276014958 m - 1.917355708m

Total head loss=9.232702 m

what are the factors that affect the coefficient of friction in surface coatings and can I get this research paper "Laser surface cladding of Ti-6Al-4V on AISI 316L stainless steel for bio-implant application"

Given that the percentage of liquefaction is estimated based on the value of Excess Pore Water Pressure Ratio( Ru = 0-1). Is there a relationship or equation between Ru and pile skin friction?

How can a more economical plan be presented by accurately calculating the amount of pile skin friction reduction in liquefied soil?

EPWPR=Ru

Ru= EPWP/ σ'v0

EPWP= Pexcess=excess pore water pressure

σ'v0=initial effective stress

Hi all,

I was just wondering if two materials (e.g: Steels and cobalt alloys) with the same coefficient of friction exhibit different wear rates. Can this be possible or not?

Kindly assist with published references.

Thanks

One of the assumptions of the masonry structures analysis is "Sliding will not occur" (Heyman`s assumptions).

In near field domain, the wave P has a strong role. It throws the objects and structures up which leads to decreasing the friction. For example, in the Bam earthquake vertical PGA was almost g: no friction. In this case, it seems that in the near field domain this analysis method is meaningless and the masonry buildings will be destroyed.

This query is very important, because in my country Iran, most of the rural houses are in near field domain.

Best,

Farzin

I am using CPD model using Abaqus (FEM) I am facing the mentioned error "The plasticity/creep/connector friction algorithm did not converge at 1 points" which aborted the Analysis. What should I do to overcome this error.

At interaction I am using Tie connection for loading and support assembly. The model Analysis completed successfully for 1 MPa or Less than 1 Mpa but when i increase the load it gives me error. The analysis started but after some increment it aborted.

As like when i used the surface to surface (Interaction) contact for loaded plated and steel roller at support then it gives me an error " Displacement increment is too big" and analysis aborted.

The model pic is attached.

Kindly share your views that I have to overcome this error.

The tri-axial shear test is the most versatile of all the shear test testing methods for getting shear strength of soil i.e. Cohesion (C) and Angle of Internal Friction (Ø), though it is a bit complicated. This test can measure the total as well as effective stress parameters both. These two parameters are required for the design of slopes, calculation of bearing capacity of any strata, calculation of consolidation parameters and in many other analyses. This test can be conducted on any type of soil, drainage conditions can be controlled, pore water pressure measurements can be made accurately and volume changes can be measured. In this test, the failure plane is not forced, the stress distribution of the failure plane is fairly uniform and the specimen can fail on any weak plane or can simply bulge.

Vfric subroutine offers to prescribe a model based on slip rate and contact pressure. However I want to include strain and use my own model for contact pressure and slip rate. Is there anybody who has experience in it?

Dear All, I am doing drilling simulation using explicit dynamics in ansys but not able to create the

**frictional**contact between two bodies. Please find the attached file in which I am not able to select contact. Please help me. Thanks in advance.Hello everyone.

Is there anyone here with hands-on experience at the implementation the Augmented Lagrangian method of contact analysis in 2D and 3D?

I know the theory and the basics and I have implemented the method in 2D and 3D. My issue is with the convergence of the method specially in 3D and when the contact has friction. I have read some papers but they don't help. I am looking forward to hearing be practical tips.

Hye;

I want to ask related to a formula for calculation of friction force for journal bearing by using CFD ANSYS FLUENT. Which formula should use ya..the first one or the second one. I find both formulas in the article. Thanks in advance.

Considering a

**four wheel skid steering heavy robot**of one ton, I need to know**the minimum torque needed to rotate itself from standstill**.Are the calculous very easy or there is a paper that is exhaustively focused on this issue?

In my opinion, the wheels torque should be greater than (i.e. win) the static friction considering that all four wheels are not rotating. Indeed the robot should move normal to its longitudinal axe which in our case coincides with the longitudinal axes of the wheels.

Other than the impact of an agricultural environment on the static friction, what is the impact of the wheel orientation?

What is the impact of the center of gravity in case it does not coincide with the center of area?

Thank you very much

Stefano

In case of turbulent flow over an irregular shape, how can we find the first layer thickness near the walls of the irregular boundary.?

For flow over a flat plate, the skin friction co-efficient can be found by the direct formula, for irregular shapes how can we find the skin friction coefficient.

Hi all,

I would like to visualise the cartilage wear on the surface of glenoid after friction test using a UV light (on macroscopic level). Could you please recommended me a florescent dye that I can use and won't affect the structural propertied of cartilage as I will be using the cartilage for histology after.

Thanks in advance.

I want Friction pile group efficiency data and I am unable to find anything about it. I want cohesion number of pile adhesion factor etc.?

A consolidated drained and consolidated undrained triaxial tests tests were done on a clay sample .. The angle of friction was greater in the CD test, but the cohesion was less ... The question is: When a footing is placed on this clay.. In which of the two tests is the settlement of the footing is greater?

Asbestos is considered the best brake friction material because of its high thermal stability, low wear rate, low cost, etc. But, due to its carcinogenic effects, asbestos has been phased out. Now, asbestos-free braking materials are being developed. Today, non-asbestos organic (NAO) brake pads are being used widely. But, NAO brake pads have low thermal stability. So, the NAO type of brake pads is not suitable for heavy-duty applications. So, which materials are ideal for heavy-duty braking applications? Metal matrix composites? Carbon-carbon composites? Ceramic composites? or any other?

I had a question revolving around the friction hardening law based on UBCSAND model utilized in CY model embedded in FLAC3D-V5. Apropos of CY model, the users are supposed to define a table of the mobilized friction angle in terms of the plastic shear strain. Inasmuch as the ensuing equations, i.e. Eq.1 and Eq.2, were posited for the frictional soils, I have tended to think of modifying the aforesaid equations so as to harness in the cohesive frictional soils medium in light of the fact that the friction hardening table in CY model ought to be adjusted to reflect more realistic behavior for a cohesive material.

Eq.1

Eq.2

Having perused HS model in PLAXIS plus CY model in FLAC3D, the formula concomitant with the elastic shear modulus has been rectified for the clayey soils as follow:

Eq.3

As respects the plastic shear modulus formula, can I have your say whether or not Eq.1 is expected to be modified with the intention of adding the mobilized cohesion?

I am trying to understand if there is a relationship between the angle of internal friction of soils and the angle at which the stress is distributed within the soil if a vertical force (via a footing) is applied at the surface.

Hello,

I'm trying to simulate an experimental contact between a truss and a constraining lateral device due to a vertical load, in ABAQUS. The contact happened because the truss had an imperfection that made it have a little horizontal displacement instead of just vertical. To simulate this in ABAQUS I used connectors with only elastic properties(non-linear) but it doesn't represent an increase in the rigidity of the force-displacement curve in the place where the load(a displacement) was applied.

So I thought about using a friction property in the connectors but I am having trouble finding the right parameters for the contact force section.

How do I find the Internal Contact force??

Thank you very much in advance.

Hi all

Im modeling interaction of soil and reinforcement in abaqus. As you know there are two obtaining parameters for soil-reinforcement interface from direct shear test of soil and reinforcement:

1. Friction coefficient between these surfaces

2. Apparent cohesion (adhesion)

for simulating mentioned interaction in abaqus I used surface to surface contact algorithm.

Friction coefficient can be defined in Tangential behavior >> Penalty method, However I can not find any way to insert apparent cohesion of interface.

It should be mentioned that Intrinsic cohesion of soil inserted as a plastic property of soil in mohr - coulomb plasticity. But apparent cohesion between these two surfaces cannot be defined in mentioned part, because this property is related in both surfaces.(its not the plastic property of one material).

Im wondering to hear any suggestion.

Thanks for your attention beforehand.

Alireza Akbari

Is it possible to change or form new chemical bonding using frictional heating during high sliding operations?

I am currently working on the dynamic mechanical analysis (DMA) of metallic glasses by molecular dynamics simulation, to investigate the Dynamic mechanical relaxation in metallic glasses. is there a relation between medium range order and the internal friction in metallic glasses? What are the atomic rearrangements that govern internal friction in glasses?

The relative importance and dominance between the forces (inertial, frictional and viscous) in a debris flow are characterized by dimensionless numbers such as Bagnold number, Savage number, Friction number etc. For calculation, we need flow depth and Interstitial fluid viscosity along with other parameters. So here I would like to ask, which flow depth we need to measure. Is it the point data where we have fixed the sensor or do we need the average depth?

Regarding the interstitial fluid viscosity, how to measure this parameter. Do we need to do rheometry or do we have any empirical formula to calculate the viscosity of a debris flow mixture.

How does lateral stiffness affect friction in general? or how lateral stiffness of vertically aligned carbon nanotube will lead to higher friction?

Fellow researchers, please help me in getting some experimental results which I can use for determining the interface stiffnesses (normal and shear), cohesion and friction angle values for debris to rockmass (preferably Phyllite and Quartzite) interface in a slope. I do not have any experimental results of the interface properties.

I have precision mirror mount, which control mirror angle by 2 positioning screws.

These screws slowly loosened during usage, so I have to rotate regularly to maintain exact mirror angle.

I first thought to apply loctite, but did not cause worrying that it might permanently fix screws immovable and become unable to adjust anymore.

Can you suggest any good method, to add little more friction to screw?

thanks,

How can I model the shear behaviour at the interface of composite layers knowing that I only have the frictional shear stress as a property ?

Youngs modulus of a material reduces with an increase in temperature. However, I would like to know what is the effect of frequency variation on Youngs modulus.

I am interested in finding reports of the use of hydrophobic coatings on metal surfaces moving in an aqueous medium that produces a reduction in friction.

I want to calculate skin friction coefficient , Nusselt and Sherwood number for different values of magnetic parameter, Prandtl number etc. in case of MHD Boundary Layer flow and Heat transfer over exponentially stretching sheet

Context: our hospital's operating area recently suffered from a tragic fire incident. Some of my instruments were left inside. Fortunately, the integrity of all of them were not compromised - all still had proper form and function. Unfortunately - they were all covered in rust.

I've attempted to restore some of them by soaking in vinegar, then vigorously rubbing a sponge - the results were more than satisfying. majority of the rust was removed. I'm just having a difficult time with the clamping ends and the hinges since they are small and the sponge can't induce enough friction due to the size difference (of the sponge and nooks and crannies). In short, I can remove most of the rust, but the tips, ends and small parts may have rust.

My questions are:

1. If I could remove all the rust, would it be safe to use them again for OR provided they have been sterilized? Sometimes I also don't know if the rust is rust or a stain that can't be removed, based on what I've already read.

2. More of my main concern is if there is a way to "dissolve" or "let the rust fall off" without the need for friction (Because of the size of instruments as mentioned). I've seen on YouTube that some have tried electrolysis to remove rust from surfaces but I think you still need to rub off some of the material.

3. If there is a better alternative than what I'm doing now (soaking in white vinegar for indefinite periods of time then rubbing the rust off)

Apologies if this is not the right platform for this kind of query - I just thought different disciplines may provide a well - thought answer to what may seem like a post for a hardware or DIY forum.

I'd really just want to be able to reuse my instruments without having to buy new ones again because the only problem with them now is rust and not integrity.

Cheers, thank you for taking the time to read this. Attached are photos of my instruments, some photos show some of the instruments already cleaned, and some show the tips and clamp ends I am worried about.

Thank you!

**Bernoulli’s Theorem**

The pore-fluids (water, oil & water) associated with an oil reservoir have internal fluid friction (or viscosity). Hence, the work done on water, oil & gas particles would remain “greater” than the respective increases in their mechanical energy – because - a fraction of work done would have got converted into heat energy through the action of internal friction.

Whether this heat energy would remain sensitive (or significant) enough at the sub-pore-scale - in influencing the reduction in Inter Facial Tension (IFT) or Wettability Reversal - associated with Chemical/Microbial EOR?

Will the generated heat energy would vary significantly as a function of API Gravity of Crude?

Hi...

I have create a piezoelectric friction damper in Ansys for seismic protection..now i wamt to add semiactive control algorithm for that damper. How i can do that..if anyone can help me....

Thank you

I have data from an experiment conducted to measure kinematic co-efficient of friction. But to know how much slipping force is required to slip the interfaces (steel plates) , I need static co-efficient of friction (the threshold value). Is there any relation available to calculate this?

Thanks!

Earth's atmospheric temperature is increasing faster than climate change models predict. Heat from anthropogenic friction may explain this observation. Conservation of energy dictates that energy used to propel and stop vehicles eventually becomes heat. This previously unacknowledged heat emanates in part from vehicular boundary layer aerodynamics and braking systems. The number of aircraft and ground-based vehicles in use suggests anthropogenic frictional heat may be a significant contributor to global warming. These observations support much wider use of regenerative braking systems.

How to set up the boundary condition for the following problem in Abaqus (Image is attached).

The feedstock will corotate with the hollow rotating tool and one pusher will push the feedstock through the tool over the substrate.

Kindly help me to set up the model. I am little bit confused with boundary conditions.

.I am trying to run my user defined properties for MOHR COULOMB plasticity.(field variable is the plastic strain).

In the input file, you can see 4 different set of mohr coulomb plasticity(in every set the 3rd variable is field variable which is "plastic equivalent strain". as ''PE".

This subroutine is for Mohr Coulomb (dependencies=1) means field variable =plastic equivalent strain

n Abaqus you can add a field parameter in your Mohr-Coulomb material and add more values of internal angle of friction and dilation angles with respect to this parameter, below you can find the corresponding lines of an input file. The values below are indicative, at "Mohr Coulomb,dependencies=1" the first value of each line is the internal angle of friction the second is the dilation angle and the third is the plastic equivalent strain (PEMAG, not PEEQ)

Below is my input file

**

** MATERIALS

**

*Material, name=SAND

*Density

1.8,

*Depvar

1,

*Elastic

8000., 0.3

*user defined field

*Mohr Coulomb,dependencies=1

37.0, 0.1,0.0

45.0, 8.,0.016

37.0, 0.1,0.09

37.0, 0.1,10.

*Mohr Coulomb Hardening

2.,0.

**

below is my attached USDFLD subroutine

I am working on a simulation of two blocks connected frictionally by surface contact, one block slides on another. I have to calculate the wear occurred on the moving block. please tell me, how to write TB wear command in Ansys APDL for this analysis and how to plot results.

I want to simulate the process as attached in the video. In reality the feedstock will have both downfeed and rotation, whereas in the video the substrate is having the rotaion and feedstock is having a downfeed.

Coupling the complete feedstock with condition of all DOF fixed except u3 and ur3 is not serving the purpose, as the feedstock will be deformed while it comes into contact with substrate i.e. radially expand.

Kindly help with the constraint to be provided in the interaction module and the load condition to simulate the process as attached in the video.

Both the feedstock and substrate is of AA6061 alloy. The feedstock is having a downfeed of 1mm/sec, and a rotation of 104.72 rad/sec.

Hopefully dynamic explicit will work well in severe plastic deformation case.

I want to understand the theoretical relationship between the functionality of the alternator and its heat generation by Joule effect and mechanical friction.

Hi!

I modeled a simplified system of two tires joined by an axle in Transient Estructural. I used a joint translational and a force applied to the axle to move the system.

Initially when the entire system and base were made of steel, the wheels turned and displaced. However when I changed the materials like rubber for the wheels surface, aluminum for the rim and axle, and concrete for the base, the wheels were slipping but no longer turning.

- I used frictional contact with a friction coefficient of 0.8 between the base and the tires
- Frictionless contact between the rim and the axle
- For the area between the rim and the tire I used the share topology in the Space Claim instead of using a contact bonded

I need the wheels to roll and turn, I have tried to change the friction parameters but cannot find the problem.

Thanks in advance