Table 4 Results of all types of NPTs under vertical load/force

Deformation of spokes (mm)

500

3.78

3.87

3.62

4

1.08

Stress in spokes (MPa)

0.64

0.66

0.68

0.49

0.36

Stress in tread (MPa)

0.216

0.2

0.21

0.21

0.2

Strain energy spokes (mJ)

0.18

0.2

0.25

0.15

0.11

Deformation of spokes (mm)

1000

7.26

7.43

7.2

7.28

3.93

5.78

Stress in spokes (MPa)

1.12

1.16

1.31

0.8

1.71

Stress in tread (MPa)

0.29

0.29

0.28

0.31

0.27

Strain energy spokes (mJ)

0.65

0.75

1.02

0.52

1.81

Deformation of spokes (mm)

1500

9.96

9.91

10.1

10.56

7.05

Stress in spokes (MPa)

1.55

1.66

1.67

1.25

2.28

Stress in tread (MPa)

0.34

0.34

0.34

0.37

0.33

Strain energy spokes (mJ)

1.24

1.57

1.81

1.29

3.18

Deformation of spokes (mm)

2000

12.15

11.7

12.42

10.07

9.81

11.15

Stress in spokes (MPa)

1.93

2.13

2.14

1.62

2.86

Stress in tread (MPa)

0.37

0.37

0.37

0.42

0.37

Strain energy spokes (mJ)

1.89

2.57

3

2.18

5.02

Deformation of spokes (mm)

2500

14.56

14.3

14.2

11.7

12.56

Stress in spokes (MPa)

2.28

2.49

2.57

2.01

3.3

Stress in tread (MPa)

0.39

0.39

0.39

0.45

0.39

Strain energy spokes (mJ)

2.58

3.51

4.34

3.37

6.67