Issue 42

M. Kowalski, Frattura ed Integrità Strutturale, 42 (2017) 85-92; DOI: 10.3221/IGF-ESIS.42.10

Dimensions, mm

, kN υ sub

, - E sub

Specimen

F m

, kN F u

, kN F p02

, GPa

w

h

B1 B2 B3 B4 B5 B6 B7 B8

12.2

3.3

20.0 17.6 18.0 18.2 17.7 18.1 17.7 18.3

16.2 14.5 14.5 14.7 15.1 14.9 14.6 16.0

12.8 15.5 12.2 13.5 11.1 14.2 13.0 14.7

0.27 0.27 0.27 0.27 0.27 0.28 0.27 0.28 0.27

151 158 157 161 155 160 155 156 157

12

2.95 2.96

11.98

12.3 12.5 12.1 12.1

3.0

2.95 2.85 2.92 3.05

11.88

Averaged

where: w, h –specimen section dimensions , E sub

– substitute Young modulus, υ sub

– substitute Poisson ratio, F m

– maximum force, F u

–Breaking force,

F p02

– foce at 0.2% strain.

Table 2 : Mechanical properties of the interface zone.

Figure 4 : Dimensions of specimen cross section.

ti E F

ti  

(1)

t t E t w E w h H E w h        

  

 

 

 

int

ti

st

2

2

int E F

int  

(2)

t t E t w E w h H E w h        

  

 

 

 

int

ti

st

2

2

st E F

st  

(3)

t t E t w E w h H E w h        

  

 

 

 

int

ti

st

2

2

Where: E ti , E in t, E st – Young Modulus of titanium, interface and steel layers respectively, F – force, w, H, h, t – characteristic dimensions of the composite. Among the specimens not used during the study phenomenon of residual stresses relaxation in titanium layer was observed. Relaxation progressed gradually in about 2 weeks after cut (Fig. 5).

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