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Response to a note by D. S. Drumheller
hf. 1. Engng Sri.. 1977, Vol. IS. p, 343.
Pergamon Press.
Printed in Great Britain
RESPONSE TO A NOTE BY D. S. DRUMHELLER
IN A RECENT note [ 11, my paper [2] was criticized for omission of references relating to a prior “discovery” of a boundary-layer effect in composites. I wish first to apologize to Dr. Drumheller for the unintentional omission of the cited references. It is merely symptomatic of the flood of literature with which every writer must contend. Secondly, and more to the point, Drumheller is apparently unaware of my earlier paper[3] predating his references, in which the existence of a boundary layer effect in reinforced composites was discussed. In any case, the existence of a boundary layer is almost self-evident. Not so self-evident is however the actual layer thickness which, according to [2], is always greater than the unit-cell dimension and related to it by the ratio of wave speeds in the constituents. For example, if the ratio is 5 : 1, the layer extends over five bilaminates and could, in principle, extend over the whole medium (if such constituents could be found). The implication (theoretical and experimental) is that pulse distortion is not generally restricted to a single bilaminate but may occur over a much larger region, depending on the wave-speed ratio. It would be interesting to have this observation verified experimentally by flyer-plate tests. The author is to be commended for an interesting note. General Electric Company Schenectady, N. Y. 12305
M.
BEN-AMOZ
REFERENCES [I] D. S. DRUMHELLER, Note on a Paper by M. Ben-Amoz. ht. J. Engng Sci. 14,795 (1976). [2] hf. BEN-AMOZ, Int. L Engng Sci. 13, 43 (1975). [3] M. BEN-AMOZ, J. Appl. Phys. 42, 13, p. 5422 (1971).(Also presented at a Colloquium on the Dynamic Behavior of Composite Materials, U. of Caliiomia, La Jolla, 1969.)
343
Pergamon Press.
Printed in Great Britain
RESPONSE TO A NOTE BY D. S. DRUMHELLER
IN A RECENT note [ 11, my paper [2] was criticized for omission of references relating to a prior “discovery” of a boundary-layer effect in composites. I wish first to apologize to Dr. Drumheller for the unintentional omission of the cited references. It is merely symptomatic of the flood of literature with which every writer must contend. Secondly, and more to the point, Drumheller is apparently unaware of my earlier paper[3] predating his references, in which the existence of a boundary layer effect in reinforced composites was discussed. In any case, the existence of a boundary layer is almost self-evident. Not so self-evident is however the actual layer thickness which, according to [2], is always greater than the unit-cell dimension and related to it by the ratio of wave speeds in the constituents. For example, if the ratio is 5 : 1, the layer extends over five bilaminates and could, in principle, extend over the whole medium (if such constituents could be found). The implication (theoretical and experimental) is that pulse distortion is not generally restricted to a single bilaminate but may occur over a much larger region, depending on the wave-speed ratio. It would be interesting to have this observation verified experimentally by flyer-plate tests. The author is to be commended for an interesting note. General Electric Company Schenectady, N. Y. 12305
M.
BEN-AMOZ
REFERENCES [I] D. S. DRUMHELLER, Note on a Paper by M. Ben-Amoz. ht. J. Engng Sci. 14,795 (1976). [2] hf. BEN-AMOZ, Int. L Engng Sci. 13, 43 (1975). [3] M. BEN-AMOZ, J. Appl. Phys. 42, 13, p. 5422 (1971).(Also presented at a Colloquium on the Dynamic Behavior of Composite Materials, U. of Caliiomia, La Jolla, 1969.)
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