In V-belt durability analysis, what concept is used to sum the damage caused by the two different tension peaks experienced by the belt as it passes over the driving and driven sheaves?
Explanation
A V-belt experiences different levels of bending stress as it wraps around the driving and driven sheaves, especially if they are of different sizes. This results in two different peak tension levels (T1 and T2) during each cycle. The Miner rule is a cumulative damage model used in fatigue analysis to estimate the total life of a component subjected to varying stress levels.
Other questions
For a flat-belt drive, what component of tension is directly related to the belt's speed and mass per unit length?
For an open-belt drive, the large pulley has a diameter of 36 inches and the small pulley has a diameter of 16 inches. The center distance is 16 feet. What is the wrap angle (ϕd) on the small pulley in radians?
What is the primary purpose of crowning flat-belt pulleys?
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For a roller chain drive, what is the term for the variation in the chain's linear velocity as it engages with the sprocket teeth?
A polyamide A-3 flat belt is 6 inches wide and has an allowable tension (Fa) of 100 lbf/in. It operates on a 6-inch diameter pulley, giving a pulley correction factor (Cp) of 0.70. The velocity correction factor (Cv) is 1.0. What is the allowable largest tension, (F1)a?
According to the belting equation for a flat belt, F1 - F2 = (F1 - Fc) * (exp(f*phi) - 1) / exp(f*phi), what is required for torque to be transmitted?
A roller chain sprocket has 19 teeth and a chain pitch of 0.5 inches. What is the pitch diameter (D) of the sprocket?
Which type of flexible element is characterized by a constant velocity ratio, no slippage or creep, and the need for sprockets instead of pulleys?
In the context of V-belts, what is the primary function of the angle-of-wrap correction factor K1?
What is the primary cause of failure for a wire rope used over a sheave?
For a standard roller chain, the fatigue strength of which component typically governs the power capacity at lower speeds?
A V-belt drive uses a small sheave with a diameter of 7.4 inches and a large sheave with a diameter of 11 inches. The center distance is 42.4 inches. What is the angle of wrap on the small sheave in radians?
What is the primary advantage of a Lang-lay wire rope over a regular-lay wire rope?
Which type of lubrication is designated as Type B for a roller chain drive?
A crossed flat-belt drive connects two pulleys with diameters of 10 inches and 6 inches, respectively. The center distance is 40 inches. What is the angle of wrap in radians, which is the same for both pulleys?
A V-belt has a nominal power rating (H_tab) of 9.46 hp. The angle-of-wrap correction factor (K1) is 0.94 and the belt length correction factor (K2) is 1.15. What is the allowable power (Ha) per belt?
What is the equivalent bending load (Fb) for a 1-inch diameter 6x19 wire rope made of monitor steel operating over a 30-inch diameter sheave? The modulus of elasticity for the rope (Er) is 12 x 10^6 psi, the wire diameter (dw) is 0.067d, and the metal area (Am) is 0.40d^2.
For a V-belt drive, if the design horsepower (Hd) is 13 hp and the allowable power per belt (Ha) is 4.878 hp, what is the required number of belts (Nb)?
What is the primary characteristic of an 'unrelated actual mating envelope' for an imperfect feature of size?
What does the pulley correction factor, Cp, account for in the calculation of a flat belt's allowable tension, (F1)a = b*Fa*Cp*Cv?
For a V-belt drive, how does the effective coefficient of friction (f') relate to the actual material-on-metal coefficient of friction (f)?
A design for a V-belt drive requires 10.25 hp. The corrected allowable power per belt (Ha) is 3.5 hp. Using a service factor (Ks) of 1.2 and a design factor (nd) of 1.1, what is the design power (Hd) and the required number of belts (Nb)?
In a roller chain drive operating at high speed, what factor becomes the primary limit on its power capacity?
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What is the primary disadvantage of using a roller chain drive with a very small number of teeth (e.g., less than 17) on the driving sprocket for moderate to high speed operation?
The total tension in a V-belt is a combination of working tensions and bending tensions. For a B-section belt with a bending tension constant Kb of 576, what is the equivalent peak tension (T1) on the driving sheave if the tight-side tension (F1) is 64.4 lbf and the driving sheave diameter (d) is 7.4 inches?
For a wire rope, the bearing pressure (P) on a sheave is estimated by the formula P = 2F / (dD). If a rope with a diameter (d) of 0.5 inches carries a tensile force (F) of 2000 lbf over a sheave with a diameter (D) of 20 inches, what is the bearing pressure?
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Which statement accurately describes the efficiency and noise level of a modern flat-belt drive compared to a V-belt drive?
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For a V-belt drive, what is the purpose of making the sheave groove angle (alpha_s) slightly smaller than the belt-section angle (alpha_b)?
What is the recommended maximum velocity ratio for a single-stage roller chain drive to ensure a successful, long-life application?
An 8x19 extra flexible wire rope has a nominal diameter of 0.5 inches. What is the approximate weight per foot of this rope?
Which factor is NOT a basis for the horsepower capacities listed for roller chains in Table 17-20?
What is the primary function of a flexible shaft?
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A three-strand No. 160 roller chain is used in a drive. The tabulated horsepower for a single strand is 56.3 hp. What is the allowable power (Ha) for this three-strand setup?
The power-drive type of flexible shaft should be rotated in which direction for optimal performance?
What is the primary reason that long center-to-center distances are NOT recommended for V-belt drives?
A 1-inch diameter wire rope is used on a stationary sheave with a D/d ratio of 20. What is the approximate percentage of strength loss for the rope?
Calculate the approximate length in pitches for a roller chain with a center distance of 25 pitches, a small sprocket with 17 teeth (N1), and a large sprocket with 34 teeth (N2).
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Which of the following flexible elements is best suited for applications requiring very long center distances?
What is the pitch length of a standard B75 V-belt?
The minimum recommended sheave diameter for a wire rope is often based on the ratio of sheave diameter (D) to the outer wire diameter (dw). What is a typical minimum D/dw ratio for elevators and mine hoists?
Which of these flexible elements is noted to have an efficiency of about 98 percent, similar to a gear drive?
A roller chain drive is operating with a 17-tooth sprocket at 700 rev/min. The chain is ANSI No. 60. What is the average chain velocity in feet per minute?