Back calculation of exciting force by 60 vibrating hammer curren

1. Force and weight are two different concepts and cannot be confused. In force analysis, weight (actually gravity) is often converted into force. The direction of gravity is perpendicular to the horizontal plane and points to the horizontal plane, or to the geocenter, but the direction of force is not necessarily; The point of action of gravity on other objects is the contact point of objects, but the force is the component of gravity. Only when the direction of gravity is the same as that of the component and on the same straight line, the force and gravity are equal.

2. Exciting force

when the centrifugal block is rotated to the highest point, the force of the plate rammer on the ground decreases<

when the centrifugal block moves to the lowest point, it provides the maximum force on the ground.
let the angular velocity of its uniform rotation be ω， If the radius is R and the mass is M1, then the centripetal force of the centrifugal block is F1, F1 = m1r ω^ 2.

the centripetal force is provided by the action of the rotating shaft on the centrifugal block F2 and the gravity m1g, F1 = f2-m1g.

therefore, the action of the centrifugal block on the plate rammer is F2 = F1 + m1g = m1r ω^ 2 + m1g.

at this time, the force acting on the ground (i.e. exciting force) is the resultant force F3 of F2 and the gravity m2 of the plate vibration rammer,
F3 = F2 + m2g = F1 + m1g + m2g = m1r ω^ 2 + m1g + m2g

it is assumed that the length of the rotating slender rod is much larger than the thickness
symbol meaning and unit

J -- moment of inertia of a rotating shaft, kg. M ^ 2
m -- mass of the revolving body, kg
I -- inertia radius, m
O -- center of gravity position< br />

3. Generally divided into two categories: 1. Elastic vibrating machinery 2. Forced vibrating machinery
vibration parameters can be calculated as follows:
YM (= 0.18 / (n / 1000) 2) * (FM / ∑ g),
am = FM / ∑ g, where YM -- double amplitude, mm
n -- Vibration times, times / min
FM -- excitation force, n
∑ -- vibration weight,
am -- vibration acceleration

4. Is it useful to calculate the strength of concrete after vibration
exciting force F = mw2r, where m is the weight of eccentric block and R is the eccentricity

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6. Forced vibration method. Natural vibration method (transient excitation method) natural vibration method is to try to make the bridge structure proce free vibration

7. Exciting force of vibrating motor: F = Mr ω 2 (n)
excitation frequency: ω= two π N / 60 (R / s)
mass of eccentric block: m -- calculated according to shape, kg
eccentric radius: R -- distance from center of gravity of eccentric block to center of rotation, m
position of center of gravity can be directly determined by coordinate method or CAXA electronic drawing software.

8. Vibratory hammers are usually used for cranes with a lifting capacity greater than 30 tons. They are used to lift (but not limited to) pipes, sheet piles and H-beams. Due to the high amplitude, they are suitable for all types of land. The maximum exciting force is 1250 kn

9. The exciting force of 90 single hammer is 570kn, the bearing capacity is determined by the pile diameter and soil quality, and the vibrating hammer has no bearing capacity.