How to calculate the axial force of drilling machine

1. For example, when you transfer money to me, I will give you a string of codes. This code is the address where I collect money. The address format corresponding to different currencies will be different, so we must repeatedly confirm whether the address is the currency in the transfer operation. For example, if you use the address of bitcoin to transfer money to the address of Ethereum, it will judge that it is not the address of bitcoin and refuse. However, if you insist on doing so, it may cause the loss of assets. So the address must be verified repeatedly before transfer. You should also pay special attention to whether the first few and the last few are exactly the same as the address given to you by the other party< When it comes to this address, it actually has another function. Blockchain is a completely transparent network. When you give someone an address, it is possible for others to query the transfer, flow and balance of your address. So when we use the address, we should also pay attention to personal privacy. For example, if you give address a to someone, you'd better give address B to another person. This is the most convenient way to protect your privacy.

2.

The axial force of AC section is - 20KN, not - 10kN. Because - 10kN acts on point C, the AC is disconnected, the left part is taken as the isolator, and only the left end bears the axial force of - 20KN, so the axial force is - 20KN. Similarly, the axial force of CD segment is - 10kN, and that of de segment is + 10kN

For columns with large slenderness ratio, the initial eccentricity caused by various accidental factors cannot be ignored. With the increase of the load, the lateral deflection also increases. The compression deformation and bending deformation of the member occur at the same time. Finally, the member is destroyed under the combined action of axial pressure and additional bending moment

firstly, the concavity compressive concrete is crushed, the longitudinal reinforcement is bent and bulged out, and the concrete cover is peeled off; At the same time, when the convex surface is under tension, the concrete will proce horizontal cracks, the lateral deflection will increase sharply, and the column will be damaged

Extended data:

for short columns with longitudinal bars and stirrups, the strain of the whole section is basically uniform under axial load. When the load is small, the concrete and steel are in the elastic stage. As the load continues to increase, the lateral deformation of the concrete increases, the fiber stress at the edge of the section first reaches the tensile strength of the concrete, and micro cracks begin to appear in the column

After

because the elastic molus of steel bar is greater than that of concrete, the stress of steel bar increases rapidly, the stress of column longitudinal bar first reaches the tensile strength of steel bar and is crushed, and micro cracks begin to appear in the column

3. If only the axial force inside the bearing is considered, there are: FA1 & gt; Fa2

please accept, thank you!

4. To find the center of mass of the rotating body (that is, the center of gravity), and measure the distance r from the center of mass to the axis, the rotational speed w (angular velocity), and the mass m, then the force is f = MRW * W.

5. The simple algorithm is resultant force, and the vector algorithm can be used for precise points

6.

1、 The necessary condition for cutting tool to cut into rock is p < sub > y < / sub > ≥ s < sub > 0 < / sub > 0· σ Where: P < sub > y < / sub > is the axial pressure on a cutting tool; S < sub > 0 < / sub > is the contact area between cutting tool and rock; σ Is the critical compressive strength of rock

Fig. 1-3-8 force system balance diagram of cutting tool when cutting into rock γ It moves downward in the direction of; γ The angle depends on the friction coefficient of rock to metal and the cutting edge angle of the cutting tool β Therefore, on the front ob, positive pressure n < sub > 2 < / sub > and frictional resistance n < sub > 2 < / sub > Tan are generated ring the cutting process φ tan φ Equal to the friction coefficient f). Similarly, positive pressure n < sub > 1 < / sub > and frictional resistance n < sub > 1 < / sub > Tan are proced on the back slope φ， See figure 1-3-8

The balance relationship of each force is as follows:

rock breaking engineering

after simplification:

rock breaking engineering

∑ f < sub > y < / sub > = 0

rock breaking engineering

after simplification:

rock breaking engineering

substitute formula (1-3-2) into formula (1-3-3), According to the conditions of cutting tool cutting into rock:

rock breaking engineering

where: B is the width of cutting tool; B is the width of cutting tool; C is the width of cutting tool; C is the width of cutting tool; σ< Sub > n < / sub > is the normal pressure (or stress) on the surface; σ Is the pressure perpendicular to ab plane, equal to the compressive strength of rock

by substituting equation (1-3-5) into equation (1-3-4), the calculation formula of axial force is obtained as follows:

rock breaking engineering

after mathematical arrangement of equation (1-3-6), the cut in depth h < sub > 0 < / sub > should be:

rock breaking engineering

cos < sup > 2 < / sup > in the right bracket of equation (1-3-7) φ/ sin β+ two φ= Z. There are:

rock breaking engineering

where Z is the cutting edge angle β And the friction angle between cutting tool and rock φ In general, z = 0.88-0.97

The

formula (1-3-8) is basically confirmed for plastic rocks. That is to say, the cutting depth is basically proportional to the axial pressure P < sub > y < / sub >, but not to the cutting tool width B and the cutting edge angle β And the compressive strength of rock. For brittle rocks, the breaking depth is greater than the cutting depth

(2) calculation of horizontal force when large shear occurs in rock e to horizontal force, the cutting tool must approximately overcome the shear resistance of rock mass with area CC ′ B ′ B and side area ABC and a ′ B ′ C ′ in Fig. 1-3-9 and the friction between the cutting tool and groove bottom

Figure 1-3-9 the resistance of the cutting tool in large shear is as follows: the area of CC ′ B ′ B is equal to, and the side area of ABC and a ′ B ′ C is equal to

When

shear aa'bb'cc ', the shear resistance is equal to:

rock breaking engineering

where: σ< Sub > 0 < / sub > is the shear strength of rock

When shearing AA ′ BB ′ CC ′ rock mass, the total resistance to be overcome is equal to:

rock breaking engineering

where f < sub > 1 < / sub > is the internal friction coefficient of rock

If equation (1-3-9) and equation (1-3-10) are equal, the relationship between P < sub > x < / sub > and P < sub > y < / sub > can be obtained:

rock breaking engineering

according to the formula (1-3-11), P < sub > x < / sub > force is related to B, h,

x < / sub > force σ< Sub > 0 < / sub >, P < sub > y < / sub >, F, and COS β In inverse proportion

7. The direction of action of the axial force is along the center line of the axis. The direction is determined. If there is no external force, the axial force (isn't it gravity?) I came out.

8. According to the cutting parameters and spindle speed into the formula can be calculated

9.

bus line: Metro Line 2, the whole journey is about 5.9km

1. Walk about 1.0KM from Shanghai Changning District Central Hospital to Beixinjing station

2. Take Metro Line 2, after 3 stops, to Zhongshan Park Station

3. Walk about 310m to longmeng Shopping Center (changningdian)