In short, rougher surfaces tend to have higher effective values whereas smoother surfaces have lower due to the friction they generate when pressed together. There are essentially two kind of coefficients; static and kinetic.
The static coefficient of friction is the coefficient of friction that applies to objects that are motionless. The kinetic or sliding coefficient of friction is the coefficient of friction that applies to objects that are in motion.
The coefficient of friction is not always the same for objects that are motionless and objects that are in motion; motionless objects often experience more friction than moving ones, requiring more force to put them in motion than to sustain them in motion. Most dry materials in combination have friction coefficient values between 0. Values outside this range are rarer, but teflon, for example, can have a coefficient as low as 0. Note that static coefficients are somewhat higher than the kinetic or sliding coefficients.
More force are required to start a motion. A lb wooden crate is pushed across a concrete floor. The friction coefficient between the object and the surface is 0. The friction force can be calculated as. The friction work energy to stop the car can be expressed as. Since the kinetic energy of the car is converted to friction energy work - we have the expression. The stop distance is not dependent on the mass of the car.
Typically steel on steel dry static friction coefficient 0. Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro.
We don't collect information from our users. Only emails and answers are saved in our archive. For instance, rubber is a common material that can have a particularly high coefficient of friction. In piping, a lower coefficient of friction generally amounts to less wear. Imagine if your pipes were being scraped against concrete. Pipe supports with a low coefficient of friction can protect pipes from damage by keeping the metal of pipes from scraping against rough surfaces around them.
Pipes need to hold up in the face of several different forces. Gravity pulls down on heavy materials in one direction, rushing liquids push in another direction, and thermal expansion can cause even more movement.
All of these forces can focus damage on a single area at high-friction points. As a pipe wears down, it can weaken, rupture, and burst. Pipe supports that reduce the coefficient of friction lower the impact on pipes. They allow pipes to move more naturally without being torn apart. When metal surfaces wear down and split open, corrosive materials can slip into crevices and cause corrosion.
From there, corrosion can spread throughout a system and weaken pipes. Friction can also scrape off protective coatings and expose bare iron to the elements. Once oxidation occurs, the iron in pipes can turn into iron oxide, or rust, which can spread quickly and destroy metal.
However, if you have pipe supports that lower the coefficient of friction, pipe surfaces move with less resistance. Thus, their surfaces maintain their integrity, and they can keep corrosion at bay. Wondering what types of pipe supports reduce coefficient of friction in piping systems? Here are a few examples.
These supports are made of fiberglass reinforced plastic FRP , which protects piping from surrounding surfaces. Hold down clamps: Lined hold down clamps, such as the VibraTek Hold Down Clamp , reduce friction and dampen vibrations at the same time. U-bolts: ProTek U-bolts are made of steel, but they include a thermoplastic coating to reduce friction wear.
With this coating, the support can direct movement without damaging the surface of pipes. Flat plates: ProTek flat plates are made of fiberglass reinforced plastic FRP and are adhered to flat surfaces, such as the structure that the pipe sits on.
In many pipe supports, fiberglass reinforced plastic FRP is the key ingredient that reduces friction.
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