PSI - Issue 44

Paolino Cassese et al. / Procedia Structural Integrity 44 (2023) 774–781 P. Cassese et al./ Structural Integrity Procedia 00 (2022) 000 – 000

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Specimen O2 showed cracking from its first set (IDR 0.10%) and also in this case the cracking force was assumed as the maximum force of such a set. Strain gauges suggested that the yielding process started at the beginning of set III (IDR 0.40%). Beyond yielding condition, some oblique cracks became more pronounced than in the previous sets until the peak condition was reached during the set IV with values of 248.8 kN (pull) and 285.8 kN (push), associated to an IDR value of 0.61%. In addition, this wall presented a cracking pattern between the upper corners of the door type opening and the lower corners of the panel. During sets V and VI softening was observed until failure occurred (IDR = 0.94%). 3.2 Panels W The experimental response of the specimens W1 and W2 is shown in Fig. 5 (a, b) and Fig. 6 (a, b) in terms of hysteretic curves and observed damage patterns at the end of the tests, respectively. Panel W1 showed some short cracks near its lateral ends since the first loading set. SGs revealed that yielding condition was reached by reinforcing steel of the outer bars reached during the set II. Consequently, the widening of some cracks and the appearance of new others still near the base of the panel were observed. The backbone curve of the hysteretic response of the W1 panel indicated that during set III a slight hardening occurs, which allowed the structural element to develop the maximum force at 0.40% IDR (324.3 kN in push; 292.0 in pull), corresponding to which existing cracks expanded widely and evolved along an average inclination of approximately 40 degrees.

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Fig. 5. Experimental Outcomes of cRCSPs: response of specimens W1 (a) and W2 (b).

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Fig. 6. Observed final damage patterns for specimens W1 (a) and W2 (b).