Deterioration of infrastructures under dynamic effects becomes a critical issue in regard to both safety and economic concerns. Deterioration itself is inevitable, but condition assessment technology and nondestructive evaluation techniques could provide solutions to ensure public safety by means of detecting damage before serious and expensive degradation consequences occur. The novelty of this issue is the use of dynamic effects and its response due to the anomalies in a structure under testing.
Waveform-based condition assessments for various structures are studied by a host of investigators using a variety of approaches. M. R. Kaloop et al. deal with structural performance assessment based on statistical and wavelet analysis of acceleration measurements of a building during an earthquake. Y. Ryu et al. present results of vibrations of classical and nonclassical damping for coupled primary-secondary systems including material nonlinearity. They use finite-element building-piping models derived from the open system for earthquake engineering simulation and carry out the Rayleigh equation to develop classical and nonclassical damping matrices for a 2-DOF coupled primary-secondary system. G. Heo and J. Jeon develop an SI (structural identification) technique using the KEOT (Kinetic Energy Optimization Technique) and the DMUM (Direct Matrix Updating Method) to decide on optimal location of sensors and to update FE model, respectively, which ultimately contributes to a composition of more effective SHM (Structural Health Monitoring).
Besides those, there are several interesting topics in the issue. L. Huo et al. propose an effective method for the damage detection of skeletal structures which combines the cross correlation function amplitude (CCFA) with the support vector machine (SVM). S.-Y. Lee deals with car crash effects and passenger safety assessment of post structures with breakaway types using high performance steel materials. In order to disperse the impact force when a car crashes into a post, the post could be designed with a breakaway feature. In his study, new high anticorrosion steel is used for the development of advanced breakaways. K.-Y. Kang et al. present qualitative analyses of the dynamic response of structures subjected to various types of gas explosion loads.
By compiling these papers, we hope to enrich our readers and researchers with respect to various waveform-based condition assessments in civil engineering.
Sang-Youl Lee
Guillermo Rus
Abdollah Shafieezadeh