Table 3 Mean values of elastic constants (GPa) and standard deviation % (SD) for heat-treated and untreated beech and birch by quasi-static tests.

From: Characterisation of thermally treated beech and birch by means of quasi-static tests and ultrasonic waves

Beech

Ref

Air

Nitrogen

150–10

200–10

250–10

150–30

200–30

250–30

150–10

200–10

250–10

150–30

200–30

250–30

EcL

15.35

13.7

14.06

12

14.17

14.04

9.46

15.72

18.81

4.58

15.8

14.55

2.52

SD

2.5

3.4

3.8

3.8

1.6

2

3.6

5.4

2

1.7

1.6

3.7

2.3

EcR

2.34

1.58

2.01

1.81

1.45

1.79

 

2.01

2.04

1

2.01

2.04

0.97

SD

0.06

0.23

0.21

0.2

0.13

0.21

 

0.2

0.17

0.25

0.16

0.19

0.16

EtL

17.07

16.64

17.23

16.9

16.42

16.24

15.79

      

SD

2.2

1.2

1.3

1.3

1.1

0.6

2.1

      

GLR

1.78

1.47

1.45

1.19

1.56

1.54

0.57

2.2

1.61

 

1.74

1.86

 

SD

0.2

0.2

0.1

0.1

0.4

0.1

0.1

0.33

0.12

 

0.28

0.24

 

vLR

0.47

0.357

0.411

0.472

0.439

0.395

       

SD

0.07

0.01

0.02

0.08

0.03

0.00

       

Birch

EcL

13.23

11.64

15.92

13.68

13.38

12.28

10.43

11.04

16.19

14.13

11.79

13.54

7.77

SD

0.4

0.5

0.5

0.4

1.4

1.6

0.9

1.5

1.2

1

2.2

1.3

2.4

EcR

0.82

1.03

0.97

0.98

0.92

1.00

 

1.15

1.1

0.56

1.03

1.13

0.46

SD

0.12

0.06

0.29

0.09

0.04

0.05

 

0.04

0.05

0.13

0.14

0.06

0.46

EtL

14.75

16.56

17.34

17.26

14.51

16.59

16.88

      

SD

3.02

3.19

3.53

3.55

0.27

2.18

2.93

      

GLR

1.22

1.16

1.15

1.07

1.3

1.37

 

1.61

1.4

 

1.51

1.29

 

SD

0.15

0.16

0.14

0.2

0.2

0.21

 

0.35

0.24

 

0.32

0.21

 

vLR

0.508

0.469

0.535

0.693

0.507

0.469

       

SD

0.06

0.00

0.05

0.05

0.01

0.02

       
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