## 3 Result Analysis
### Steel Rebar, Steel Plate, and Concrete Strain
Subsequently, the strain of the beam\(-\)web concrete strain gauge 2 begins to respond and stabilize after gradually increasing to the peak tensile strain. During the strain response process of the beam web, the strain of the concrete strain gauge 3 at the bottom of the beam rapidly increases to the ultimate tensile strain value, indicating that the transfer of the stress wave to the bottom of the mid\(-\)span beam causes the concrete in the tension zone to crack and quickly stop working. The concrete strain variations are shown in Figure 18b for the quarter\(-\)point section. The strain response times of concrete strain gauges 4 and 5 are almost the same, while the strain response of concrete strain gauges 6 has a lag, which indicates that the time\(-\)consumption of various transmission paths of stress waves in the beam is quite different. The stress wave that is transmitted to the concrete strain gauge must first travel to the bottom of the beam along the height direction before being transmitted horizontally to both sides. The stress wave that propagates along the length of the test beam is the fastest among these. At the top of the beam, the concrete is in tension mode at the start of the impact and reaches the peak tensile strain after a slight shock. The concrete at the top of the test beam is under tension because, throughout the impact process, the stress wave is transferred to both sides, and the negative bending moment area gradually travels to the quarter\(-\)point. The tensile strain of the beam web increases gradually after the response and increases rapidly to the maximum tensile strain after experiencing the first wave peak, and finally stabilizes at a lower strain value. The beam bottom strain increases rapidly after the response, decreases rapidly after reaching the peak tensile strain, and turns into compressive strain, indicating that the test beam's failure modem strengthened with bonded steel is relatively complex at the quarter\(-\)point. When the beam is deflected, the bottom of the test beam is in tension, and with the tension of the steel plate, the cohesive failure of the concrete at the quarter\(-\)point occurs, and the concrete in this section is compressed. The overall variations in the concrete strain are depicted in Figure 18c. The stress wave transmission has a substantial impact on the strain response of the concrete material, as seen by the wide variations in the strain signal's first response time. The stress wave has the fastest oblique transmission speed, while the transmissions along with the height and horizontal directions are relatively slow. Compared with Figure 16c, the response of the stress waves to concrete is more significant than that of the steel rebars. It can be seen in Figure 18c that the damage to the concrete at the mid\(-\)span section is more severe than that at the quarter\(-\)point. The beam top and bottom of the mid\(-\)span section have the most damage, while the beam web and beam top of the quarter\(-\)point section are more seriously damaged. This is because the top failure of the mid\(-\)span beam mainly occurs at the local damage stage of the impact and is significantly affected by the inertial force effect. However, the mid\(-\)span beam bottom and the beam web and beam bottom of the quarter\(-\)point section mainly occur in the overall failure stage of the impact. Both the overall flexural deformation of the test beam and the peeling of the steel plate have a significant impact on the peeling and cohesiveness of the concrete cover. Through the abovementioned analysis, it is not difficult to conclude the following load transfer law: the impact load acts on the middle part of the beam, generates bending moment and shear force, and causes the beam to undergo bending deformation, and the impact force is propagated in the form of a stress wave along the direction of the beam height and length, which results in the beam's local and overall response.