The setting of Acoustic Emission detecting parameters in running of steel structured
Acoustic Emission technology is still at the starting stage of monitoring in domestic bridge. To resolve the problem that Acoustic Emission detection parameters in scene are determined. Based on lead-breaking tests confirm threshold and time parameter. Studying on the characteristic of signal propagated and the attenuation laws of velocity and amplitude, it gets references for Acoustic emission technique in detection of the bridge.
Study on the AE Characteristics of Cracking Process in Prestressed Concrete Beams
A series of prestressed concrete beams were loaded at three points subjected to bending until failure.The waveform acoustic emission signals were recorded.Crack initiation and propagation due to bending were monitored and compared with observation.Based on the relationship between the cumulative energy of acoustic emission and time,the waveform acoustic emission signals of different destruction states was picked up and spectral analysis was carried out.According to the value of the energy amplitude of waveform acoustic emission and the comparison of the amplitude and frequency of waveform acoustic emission signals in time domain and frequency domain,different damage stages of the prestressed concrete specimens until failure were divided,and the parameter properties of prestressed concrete specimens were picked up.The research shows that waveform acoustic emission signals can be used to find the characteristics of the different damage stages of prestressed concrete beams under loading in real time.
CULTURE, SUSTAINABLE URBAN DEVELOPMENT AND URBAN REGENERATION
Concerns about the conflict between economy, development on one hand and urban cultural heritage on the other hand, have made the urban development to be lately one of the most important themes at European level. Also, another issue of concern is social equity, aiming to strike a balance between economic development and equal access to culture for all generations of inhabitants of urban communities. Basically, ensuring these balances between urban cultural heritage, economy and social equity we express the essence of the concept of sustainable development from the perspective of culture. Urbanization is an ongoing process in all the cities of the world, but urban cultural heritage is a crucial element in the development of the cities and has an important impact over the quality of life of that community. Castles, churches, fortresses, squares and public buildings all contribute at the creating of the community history and of their characteristics.