Abstract: An evaluation method for corrosion damage evolution of underwater concrete structures includes performing the time reversal test on the concrete beam specimen placed in the water, performing the uniaxial compression test on the concrete cube specimens; immersing the concrete beam specimen and the concrete cube specimens in a hydrochloric acid solution, and performing the time reversal test on the concrete beam specimen on the 10th, 20th and 30th days respectively. At the same time, a concrete cube specimen is taken out to perform the uniaxial compression test on the 10th, 20th and 30th days respectively; and using the above calculation results to evaluate the corrosion evolution process thereof without damaging the underwater concrete structure.

Abstract: A boundary adaptive structural fatigue damage detection method driven by time-domain information entropy comprises a sensor sequence composed of several sensors arranged on the structure, which is used to apply excitation to the structure, collect the displacement time-history response curves at different positions on the structure, and establish a database of time-history data. According to the data set in the database, the information entropy of the time-history response at different positions on the acquisition structure is obtained based on the information entropy to measure the disorder degree of the time-domain response signal. According to the location of several sensors, the information entropy values of the time-history response are connected in turn to obtain the time-history information entropy curve of the whole structure. Analyze of time-history information entropy curve, and the information entropy curve will show jump phenomena to determine the location of the crack.

Abstract: A damage identification method for a cantilever beam based on a multifractal spectrum of a multi-scale reconstructed attractor includes: acquiring an original acceleration signal of the cantilever beam by a dynamic measurement system, performing stationary wavelet decomposition on a pretreated acceleration signal to obtain multi-scale sub-signals, selecting the multi-scale sub-signal that can represent main vibration characteristics of the cantilever beam for phase space reconstruction and normalization to obtain a normalized multi-scale reconstructed attractor, constructing the multifractal spectrum of the multi-scale reconstructed attractor, establishing a damage index based on a singularity index of the multifractal spectrum, and identifying and locating damage of the cantilever beam according to a relative numerical value of the damage index.

Abstract: A cable tension calculation method simultaneously considering the sag, inclination angle and bending stiffness includes: querying basic parameters of a stay cable according to design data and construction data; considering influences of the sag, the inclination angle ? and the bending stiffness EI, to calculate dimensionless parameters ?, ? and ?2; testing an acceleration response of the stay cable by an acceleration sensor, to identify a frequency ? of the acceleration response of the stay cable, further calculating a dimensionless frequency {circumflex over (?)} of the stay cable and the dimensionless parameters ?, ? and ?2, and substituting the dimensionless frequency {circumflex over (?)} of the stay cable into a vibration characteristic equation, to establish a function relation between the dimensionless frequency {circumflex over (?)} and a cable tension H* of the stay cable; and solving a root of the vibration characteristic equation, and identifying the cable tension H* of the stay cable according to

Abstract: A structural dynamic parameter identification method aided by a rPCK surrogate model comprises the following steps. Establish a finite element model that roughly reflects the structural system to be analyzed. Establish the dynamic parameter space sample set. The structural system response space sample set driven by the dynamic parameter space sample set is established by using the probabilistic finite element analysis. The robust polynomial Chaos Kriging surrogate model is obtained by mapping the dynamic parameter space sample set to the structural system response space sample set. The measured structural system response is used to drive the rPCK surrogate model, and then Bayesian inference is used to identify the structural dynamic parameters. The mean value of Bayesian posterior estimation is used as the estimated value of structural dynamic parameters. The proposed method creates conditions for establishing a high-fidelity finite element model of the actual engineering structural system.