# Shear Resistance Assessment of the Y-Type Perfobond Rib Shear Connector under Repeated Loadings
## 5 Residual Shear Strength Design Procedure under Repeated Loads  
### Energy Dissipation Models under Repeated Loads  
The energy dissipations per one repeated load cycle are summarized in Tables A1-A4 depending on the load intensities from 785 to 1460 kN. For the relatively low intensities, such as 785 and 1010 kN, the average values of energy dissipations per cycle converge reasonably after 3 cycles of repeated loads, even though the variation of the energy dissipations for 12 specimens is quite large: from 10 to 50 kN\(\cdot\)mm for 785 kN loads (35% of ultimate shear strength) and from 20 to 90 kN\(\cdot\)mm for 1010 kN loads (45% of ultimate shear strength). For the repeated load of 1235 kN (55% of ultimate shear strength) the average energy dissipation converges after 10 cycles as shown in Table A3, in which some specimens are loaded repeatedly up to 50 times. For the repeated load of 1460 kN (65% of ultimate shear strength) the average energy dissipation converges also after 9 cycles as shown in Table A4, in which some specimens are loaded repeatedly up to 15 times. The difference of energy dissipation continues to decrease slightly with increasing cycles after the convergence is achieved. This part will contribute to the conservative estimation of total energy dissipation due to the repeated loads during the service life of the structure in the design stage. To establish the energy dissipation models per one repeated load cycle, 24 energy dissipation results from the 4 th and 5 th cycles were selected for the sample sets of 785 and 1010 kN loads, respectively. For the 1235 kN load sample set, 24 energy dissipation data were collected from the 10 th to 13 th cycles, that is, 6 data from each cycle as shown in Table A3. For the energy dissipation model of 1460 kN load, 23 data were collected from the 9 th to 15 th cycles to generate the sample set as shown in Table A4. Due to the limited number of specimens, the repeated loading tests with the load types 4 and 5, were performed with selected specimens, that is, 7 specimens out of 12 specimens continue to be tested after 5 cycles of 1235 kN load as shown in Table A3. The other 5 specimens were tested under different loading types (load types 1-3). Based on this, the energy dissipation trends are investigated in Figure 12. The selected 6 specimens for more than 5 cycles of 1235 kN load test (the solid-lined box, 1235-L in Figure 12) show relatively low energy dissipations during the 1010 kN loads (1010-L1 group in Figure 12) compared to the other 6 specimens, which continue to be loaded with 1460 kN after 5 cycles of 1235 kN load. In Table 17, the order of energy dissipating amounts is provided from 1-2 for 785 and 1010 kN loads in the increasing order, and 1-2 for 1235 kN load, and 1-4 for 1460 kN load. In 785 and 1010 kN columns of Table 17, two averages are provided: one is the average of 12 specimens and the other is the average of 6 selected specimens, which are loaded with 1235 kN repeated loads after 1010 kN repeated loads. One specimen is excluded: No.10 specimen, that is ordered with 7 in 1235 kN column, because the energy dissipation amount of No.10 specimen is quite large compared to the other 6 samples. The trend is similar in 785 and 1010 kN. For the 1010 kN loads, the average of the selected 6 specimens (1-6 in 1010 kN column) is only 25.99 kN\(\cdot\)mm (Average-2), and much lower than the average of whole sample, 45.44 kN\(\cdot\)mm (Average-1). Under the repeated loads of 785 kN, two groups of specimens show a very similar trend. Therefore, the expected average of 1235 kN loads may be much larger than 51.07 kN\(\cdot\)mm, which is obtained from the selected 6 specimens. Based on this, the ratios of the mean values of 785 and 1010 kN loads were utilized to revise the average value of 1235 kN load. To establish the energy dissipation model for 1460 kN load, the average energy dissipation values of No.6 and No.9 specimens were selected as the representative mean value.