Online Sifting Technique for Structural Health Monitoring Data Based on Recursive EMD Processing Framework

Round 1

Reviewer 1 Report

This paper presents a processing method for data collected in a structural health monitoring system. The method uses a recursive approach that adapts in real-time to better process data, compared to prior methods. The proposed method is illustrated using strain data from a three-span bridge with girders that have been instrumented with strain gauges. The paper is well-written. In my opinion, the technical content is also sound. I have three suggestions for improvement.

1. Explain how the proposed method, which was illustrated for bridges, could also be applied to buildings, which are the focus infrastructure of this journal. As is now reads, the paper was not persuasive that the method could also be applied to building science, building engineering and architecture.

2. In my opinion, the conclusions section is too brief. Please consider expanding the conclusions section by discussing the implications of the findings, as illustrated in the bridge example. Perhaps the previous suggestion (i.e. application to buildings) could be addressed here.

3. Clarify the structure and instrumentation of the example bridge. As it now reads, important details of the bridge and the structural health monitoring system are missing. For example, was the girder a prestressed reinforced concrete section? Were the strain gauges embedded in the girder or mounted on the girder? What type of strain sensors were used? Were they fiber optic sensors or some other type of sensor? How was the sensor interrogated? How was the data collected? Remotely or manually? In my opinion, the paper would be strengthened by better describing the structure and the instrumentation in more detail.

Author Response

Thank you very much for taking the time and effort to review this manuscript. Our response is uploaded as an attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

In this study, the authors developed an online sifting technique using the recursive EMD signal processing and applied this technique on bridge health monitoring. The research topic is interesting, and this work has the potential of advancing the state of the art of vibration-based structural health monitoring. The manuscript is well written. Please see below for some minor comments.

1.       Please use the full spelling for all acronyms (e.g., EMD) when they appear for the first time.

2.       In Line 40, should it be “sifted” instead of “shifted”?

3.       In Section 4 and 5, please show the results of traditional EMD method, at least for some of the plots, to demonstrate the advantage of online sifting technique using the recursive EMD.

Author Response

Thank you very much for taking the time and effort to review this manuscript. Our response is uploaded as an attachment.

Author Response File: Author Response.pdf