PSI - Issue 72

Victor Rizov / Procedia Structural Integrity 72 (2025) 120–127

125

through Eq. (18).

f F 2 , is determined too. Equation (24) is applied for dealing with

The SERR in the frame in Fig. 1b for the load,

static indeterminacy.

U



6 D H F

2 

(24)

0

.

R



After that, the SERR is derived through Eq. (10). The result is checked-up by Eq. (19). The frame in Fig. 1c is explored at last. First, the static indeterminacy is treated. The frame in Fig. 1c has two degrees of static indeterminacy. The horizontal reaction and the moment, 6 D M , in the fixed support in point, D6, are taken for hyperstatic unknowns. Thus, Eqs. (25) and (26) are used for resolving the static indeterminacy under load, F 1 .

U



6 D H F

1 

(25)

0

,

R



 RM U

F

6 1  D

(26)

0

.



Then, Eq. (10) is applied for determining of the SERR. Equation (18) is used for check-up. The treatment of static indeterminacy in the frame in Fig. 1c under load, F 2 f , is done via Eqs. (27) and (28).

6 D H R U f F RM U f F 2

 

0

2 

(27)

,



0



(28)

.



D

6

The SERR is determined by Eq. (10). A check-up is done via Eq. (19). 3. Results The curves exposed in the next four figures in this paragraph of the article give clearness to the question for the effect of support conditions on the SERR in the frame under periodic dynamic loading.