Active Tendon Control of Stay Cable by a Giant Magnetostrictive Actuator Considering Time-Delay

Round 1

Reviewer 1 Report

The authors present a study on active control of a cable with time delay effect, their numerical results are validated with experimental work. Although only first-order modal response is validated it seems to be an interested work. 

• A scaled-down cable model is used to validated simulations; however, the author did not discuss regarding the current or power consumption of the actuator. I believe this is a major concern when dealing with real structural members.
• Equations 33 and 34 present the relationship of control force and input voltage for ascending and descending stage. I suggest presenting the characterization curves of the actuator, it is expected to appear hysteresis, if so, how this is considered on the control equations.
• From figures 6 to figure 12 is difficult to see nay difference between the cases without time-delay (blue) and whit time-delay compensation (red). Is it possible to add some magnification on critic zones that provides a better comparison?
• Detail description of the control system is missed, for example: sample ration and features of laser sensors, signal acquisition and processing.

Author Response

Please see attached file.

Author Response File: Author Response.doc

Reviewer 2 Report

This is an interesting manuscript but needs a detailed improvement for further consideration. The results are as expected for this simple lab-scale experiment. The authors identified correctly the shortcoming of the original work from other authors in [24] and incorporate the time delay properly.

Overall, the manuscript could be shortened by at least 30% without losing readability.

The derivation of Eq. (32) is very lengthy and could be condensed easily. Eqs. (26, 27) could be deleted because their content is anyway shown again in Eq. (28). I do not see an added value of providing the details of the coefficient matrices in Eq. (10).

Something is wrong with the formatting of the equations. Eq. (24) is squeezed horizontally, Eq. (11) seems squeezed vertically, Eq. (12) seems fine.

Fig. 1 is of low quality and needs improvement.

All figures having two graphs could be fitted into a single line, for example Fig 3a on the left and Fig. 3b on the right.

A proper reference to the Ricatti equation given in Eq. (21) is missing. This equation was not invented by the authors.

The blue curve in Figs. 6 and 8 is not visible.

One main step is Eq. (29). A proper reference to the original work where this idea was brought up the first time should be added.

Author Response

Please see the attached file.

Author Response File: Author Response.doc

Round 2

Reviewer 2 Report

Almost all points were adressed accordingly.

The manuscript could be condensed to approximately 14 pages without loosing readability. For example, Eq. (9) could be written in a single line by introducing an index i = 1,2,3. Line 123 on page 4 could be written in two lines instead of 6 lines. Also lines 131, 132, 133, 134 and 135 could be deleted, since they are derived trivially from Eq. (9).

Lines 170 and 171 on page 5 could be written in a single line. The same holds for Eq. (18), lines 189 and 190 on page 6, and son on.

Line 254 on page 8 could be deleted.

The authors should check in detail, which equation could be condensed or deleted entirely for the rest of the manuscript.

The reference list needs to be edited properly. All names should be given (no "et al."). Some first names are spelled fully, some are abbreviated, e.g. [1] and [2]. Check the "guide for authors" for proper formatting. Some titles have "" some not. [6] has "&", the others do not have this. Some names are written with the first name at the beginning, some with the first names at the end, e.g. [30] and [31].

 

Author Response

Please see the attached file.

Author Response File: Author Response.docx