PSI - Issue 36

Volodymyr Iasnii et al. / Procedia Structural Integrity 36 (2022) 284–289 Volodymyr Iasnii, Lukasz Sobaszek, Petro Yasniy / Structural Integrity Procedia 00 (2021) 000 – 000

286

3

Fig. 1. Scheme of the damping device.

3. The experimental results and their discussion The experimental results show strict dependence of hysteresis loop shape on the frequency (Fig. 2). This process can be described quantitatively by dissipated energy per cycle and loss factor. This factor is the efficient parameter to describe the damping device capability and calculated as damping capacity per radian cycle by formula (Soul and Yawny (2015)):

W



,

=



(1)

2

W



where  W is dissipated energy; W is strain work measured under the maximum displacement. Hysteresis loops in the coordinates of applied force – device displacement are shown on Fig. 2. It should be mentioned, that the strict dependence of hysteresis loop shape on the displacement amplitude of rod is observed. On the base of hysteresis loops, one can quantitatively calculate the functional characteristics of the damping device such as energy dissipated within the complete cycle of the loaded device and loss factor. The loss factor is the efficient parameter of damping device capability assessment and is defined as damping capacity (capability) per radian of cycle.

1 cycle 2 cycle 3 cycle 4 cycle 5 cycle 6 cycle

1 cycle 2 cycle 3 cycle 4 cycle 5 cycle 6 cycle

a)

b)

0,0 0,5 1,0 1,5 2,0

2,0

1,0

0,0

P, кН

-10

-5

0

5

10

-10

-5

0

5

10

-2,0 -1,5 -1,0 -0,5

P, kN

-1,0

-2,0

Displacment, mm

Displacment, mm

Fig. 2. Summary of the results for tested frequencies 0.001 Hz (а) and 0.1 Hz (b). The individual curves represent the device response. The different coloured curves correspond to the different amplitudes of 3, 4, 5, 6, 8 and 9 mm imposed on the tests (a) first picture; (b) second picture. Hysteresis loops (applied force – SMA wire strain) are shown on Fig. 3.