Dynamic study of cable lines transporting dragon fruit in the Southwest region - 2

Unit

Meaning

L

m

Cable length

γ

N/m

Cable specific gravity

q

N/m

Evenly distributed load

q k

N/m

Uniformly distributed load of kth span

Q

N

Total load on cable

P

N

Total weight of cable

T

N

Tangential cable pull

cm

Distance between 2 pulleys

k

cm

Distance between 2 pulleys at kth span

H

N

Horizontal tension (abbreviated as horizontal tension)

R

N

Vertical tension

R y

N

Vertical force at pulley

R k

N

Vertical force at kth span

T(x)

N

Tension in the string at x

f

cm

Cable span at midpoint (two equal supports)

f k

cm

Cable loop at kth span at midpoint (two equal supports)

f c

cm

Height difference from C lowest point of the rope to the support pulley

high end of cable span (two supports with different heights)

f w

cm

Elevation difference of lowest point C of cable span

with the cable end pulley point moving out of the span

f​

Hz

Wind frequency

 s

cm

Length element at x

 ( x )

N/ cm2

Tensile stress at point x

 

cm

Elongation at point x

 L

cm

Elongation of cable under tension

L 0

cm

Length of cable without load

cm

Length of cable section under load

 L ( k )

cm

Elongation of cable when stretched at kth iteration

L k

cm

Cable length at kth iteration

E

N/ cm2

Elastic cable module

F

cm 2

Cross-sectional area of ​​cable

h

cm

Height difference between two support pulleys



degree

Angle between tangent to cable and Ox direction

P max

N

Maximum basket weight



degree

Angle between the line connecting the 2 supports and the OX direction

F x

N

Cable pull

F c

N

Work force when cable moves

F n

N

Horizontal friction force

F p

N

Frictional resistance

M

kg

Mass of cable at node A, N

m

kg

Weight of basket and dragon fruit

g

m/s 2

Acceleration of gravity



degree

The angle between the basket containing dragon fruit and the vertical

r

cm

Length of hanging wire for dragon fruit basket

F qt

e

N

Inertia of dragon fruit basket

x ( t )

m/s 2

Acceleration of dragon fruit basket

v

m/s

Contact point velocity

We​

m/s 2

Centripetal acceleration of dragon fruit basket

W t

n

m/s 2

Tangential acceleration of dragon fruit basket

R pl

cm

Pulley radius

F ( t )

N

Wind force

t

S

Time

S

cm

Distance between two dragon fruit baskets

A

cm

Maximum oscillation amplitude of dragon fruit baskets

Nm/s

Power consumption

W m

Nm/s

Power consumption overcomes friction

W k

Nm/s

Power required to move the cable on the cable span

a tb

m/s 2

Average peak acceleration value

a i

m/s 2

Acceleration value of the i-th measurement

X

Overall sample mean

S m

Test sample standards



Experimental significance level



Absolute error of estimate

n ct

Sample size required

S 2 m

Maximum variance in total number of experiments

S 2 u

Experimental variance u with number of replications u

ball​

Variance of regression coefficient

S 2

e

Variance due to noise

m u

Number of repetitions at each experimental point

Yes​

Value of output parameter at point u

Y u

Average value of output parameter at point u

G tt

Kohren value by calculation

F tt

Fisher value by calculation

Table name

Page

3.1

The length L (cm) of the cable is calculated according to the values ​​of f and

71

3.2

The rotation f (cm) is calculated based on the horizontal tension H (N) and (cm) when loaded

uniform weight q = 0.2 (N/cm)

72

3.3

Steps to approximate the equations W( u )  0

75

3.4

Elongation  L and curvature f with respect to initial length L 0 and load q

76

3.5

Error of L and f values ​​between the 4th and 5th iterations.

76

3.6

The horizontal tension force H and reaction force R y at the closed cable support have

same height

77

3.7

Calculate the rotation f , R c , R t on the cable span with bearings of different heights

84

3.8

Calculation results for closed cable line with 23 spans, length 50000 cm

85

3.9

Horizontal and vertical resonant frequency region of the basket on the span

90

3.10

Maximum oscillation amplitude of the baskets according to the positions suspended on the cable

93

3.11

Maximum oscillation amplitude (m) of the basket corresponding to H values

95

3.12

Maximum oscillation amplitude (m) of the basket corresponds to the values ​​when

H=3500N, S=0.80m, r=0.30m

96

3.13

Maximum oscillation amplitude (m) of the basket corresponding to r values

97

3.14

Power consumption of the cable system corresponding to the total cable length

and total number of redirects in the system

98

4.1

Comparison results of the effects of span length and transverse tension on

maximum cable loop

114

4.2

Comparison results of the effects of span length and transverse tension on

amplitude of oscillation

115

4.3

Effect of cable tension on loop length when span length

=2200 cm and evenly distributed load q = 0.2 N/cm

115

4.4

Effect of cable horizontal tension on polar oscillation amplitude

basket size in mid span

118

Effect of span length on lap under horizontal tension

H = 5500 N and uniform load q = 0.2N/cm

120

4.6

Effect of cable span length on maximum oscillation amplitude

122

4.7

Experimental level of input parameters

124

4.8

Matrix table of the test of the rotational force f depending on the horizontal tension H and

span length

125

4.9

Experimental matrix table of maximum oscillation amplitude of the basket at the suspension point

between spans depends on horizontal tension H and span length

125

Image name

Page

1.1

Dragon fruit harvesting technology diagram

5

1.2

Cut dragon fruit with scissors

7

1.3

Moving dragon fruit by manual carrying

7

1.4

Moving dragon fruit with cart

8

1.5

Moving dragon fruit with tractor

8

1.6

Loading and unloading dragon fruit to transport to the place of consumption

8

1.7

Dragon fruit is dumped in piles or stacked in plastic crates.

9

1.8

Fixed single wire cable diagram

12

1.9

Single wire cable diagram tension - slack

13

1.10

Shuttle type single wire cable diagram

14

1.11

Single wire cable in closed loop

14

1.12

Three-wire motorized cable

15

1.13

Three-wire non-powered cable

16

1.14

Three-wire motorized cable

17

1.15

Structural diagram of 3-wire continuous circulating transmission cable line

18

1.16

Transporting custard apples by cable in Chi Lang, Lang Son

20

1.17

Orange transport cable line in Ham Yen

21

1.18

Banana post-harvest cable line

21

1.19

Southwestern dragon fruit garden

28

1.20

Dragon fruit cable transport model

29

2.1

Dragon fruit cable transport model

37

2.2

Closed loop cable calculation model

38

2.3

The cable rests on two pillows of the same height.

40

2.4

Model for calculating cable tension

40

2.5

Calculate the elongation of the cable

42

2.6

Closed loop cable calculation model

45

2.7

Model for calculating the bearing capacity of the wire on bearings with different heights

49

Dynamic diagram of dragon fruit transport cable line

57

2.9

Force analysis diagram in calculating the vibration of dragon fruit basket

58

2.10

Diagram of force analysis on the basket during cable transfer

direction

63

2.11

Model to calculate power consumption to move the dragon fruit basket on

cable span

68

3.1

Calculate the elongation of the cable

75

3.2

Cases where the cable rests on two bearings with different heights

79

3.3

Graph of cable loop equation when the support has different height

84

3.4

The graph shows the basket's oscillation at the mid-span position of the cable.

87

3.5

The phenomenon of horizontal oscillation beat when wind frequency f z = 5.4

90

3.6

Resonance phenomenon of horizontal oscillation when wind frequency fz = 5.9

91

3.7

The phenomenon of longitudinal oscillation beat when wind frequency fx = 5.3

91

3.8

Resonance phenomenon of longitudinal oscillation when wind frequency fx = 5.4

91

3.9

The beat phenomenon of oscillation when the basket changes direction with wind frequency f

= 5.5

92

3.10

Resonance phenomenon of oscillation when the basket changes direction with frequency

wind f = 5.6

92

3.11

Graph of maximum horizontal oscillation amplitude of dragon fruit basket according to

basket hanging position

94

3.12

Graph of maximum oscillation amplitude of hanging basket corresponding to tension forces

different widths, with length r = 0.3 m, = 2400 cm

95

3.13

Graph of maximum oscillation amplitude of the basket corresponding to change

96

3.14

Graph of maximum oscillation amplitude of hanging basket corresponding to basket wire length r

different, when horizontal tension H = 3500N, = 2400 cm

97

3.15

The graph shows the dependence of power consumption on the horizontal tension of the string.

cable and number of pulleys

99

4.1

Block diagram of experimental equipment

104

4.2

B12/1000 vibration amplitude measuring sensor

105

4.3

Wheel level measuring device

106