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A comparison between modal damping ratios identified by NExT-ERA and frequency domain impact test | ||
| Journal of Computational & Applied Research in Mechanical Engineering (JCARME) | ||
| مقاله 2، دوره 8، شماره 1 - شماره پیاپی 15، آذر 2018، صفحه 15-24 اصل مقاله (1.02 M) | ||
| نوع مقاله: Research Paper | ||
| شناسه دیجیتال (DOI): 10.22061/jcarme.2017.1552.1128 | ||
| نویسندگان | ||
| Ali Nouri* 1؛ Sajad Hajirezaee2 | ||
| 1Department of Aerospace Engineering, Shahid Sattari Air University, Tehran, Tehran | ||
| 2Department of Aerospace Engineering, Sharif University of Technology, Tehran, Tehran | ||
| تاریخ دریافت: 02 خرداد 1395، تاریخ بازنگری: 16 مهر 1396، تاریخ پذیرش: 16 آبان 1396 | ||
| چکیده | ||
| In this research, the modal parameters of a beam in free-free condition are extracted by performing different experiments in laboratory. For this purpose, two different techniques are employed. The first methodology is considered as a time domain method in Operational Modal Analysis. While the other one is frequency domain impact hammer test which is categorized as an Experimental Modal Analysis method and can be regarded as the most common method in modal analysis. Checking the results obtained by the two methods, one can notice a distinct inconsistency in modal damping ratios extracted by each method. However, based on recent publications on the subject, it can be inferred that the time domain methods have better accuracy in identifying damping ratios of structures. In order to confirm the findings, the effect of excitation is examined for each method by altering the excitation tool. For the operational method, it is concluded that changing the excitation tool will not have a noticeable influence on the identified damping ratios, whilst for the Experimental Modal Analysis method changing the hammer tip leads to inconsistent results for damping ratios. This study exemplifies the deficiency of Experimental Modal Analysis methods in their dependency on excitation techniques. | ||
| کلیدواژه‌ها | ||
| Operational Modal Analysis؛ Time Domain Method؛ Frequency Domain Method؛ Modal Damping Ratio | ||
| مراجع | ||
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