Lower String Research Articles

Static performance of a new GFRP–metal string truss bridge subjected to unsymmetrical loads

A unique lightweight string truss deployable bridge assembled by thin-walled fiber reinforced polymer (FRP) and metal profiles was designed for emergency applications. As a new structure, investigations into the static structural performance under the serviceability limit state are desired for examining the structural integrity of the developed bridge when subjected to unsymmetrical loadings characterized by combined torsion and bending. In this study, a full-scale experimental inspection was conducted on a fabricated bridge, and the combined flexural–torsional behavior was examined in terms of displacement and strains. The experimental structure showed favorable strength and rigidity performances to function as deployable bridge under unsymmetrical loading conditions and should be designed in accordance with the stiffness criterion, the same as that under symmetrical loads. In addition, a finite element model (FEM) with a simple modeling process, which considered the multi segments of the FRP members and realistic nodal stiffness of the complex unique hybrid nodal joints, was constructed and compared against experiments, demonstrating good agreement. A FEM-based numerical analysis was thereafter performed to explore the effect of the change in elastic modulus of different FRP elements on the static deformation of the bridge. The results confirmed that the change in elastic modulus of different types of FRP element members caused remarkable differences on the bending and torsional stiffness of the hybrid bridge. The global stiffness of such a unique bridge can be significantly enhanced by redesigning the critical lower string pull bars using designable FRP profiles with high elastic modulus.

Even unto Death: Improvisation, Edging, and Enframement

I begin to play. I take my first two notes on open string almost as if they were a transition from tuning into music. As I play the first few slow notes I hear from different points of the dark hall the indrawn breath of startled recognition. After my four lonely bars, Piers joins me, then Billy, and then Helen. We are playing the first contrapuntus of Bach's Art of Fugue. We play almost without vibrato taking open strings whereever they fall naturally, even if it means our phrases do not exactly replicate one another. We play with such intensity, such calm that I never imagined we could either feel or create. As I move to the tiny quaver, the miniscule quibble of a note that has been the source of all my anxiety, Helen who has a rest here turns her head slightly and looks at me. I can tell that she is smiling. It is the F below middle C. I have had to tune my lowest string down a tone in order to be able to play it. We play in an energized trance. These four and a half minutes could be as many hours or seconds. We are one with each other, with the world and with that long dis-

Mesopotamian tonal systems

In his article “Babylonian Music Again”, O. R. Gumey provides a welcome update on research on the tablets concerning music of the ancient Near East. Gurney's article also has a corrective effect on a rambunctious article by Martin West that appeared shortly before. Gurney seems to me to have the musical system almost right. West, while he seems to understand the system, presents it in ways that I find illogical, and that I fear will be confusing or misleading. Furthermore, while some of West's conclusions exceed the span of even my own irresponsible imagination, some of his other conclusions seem unnecessarily restrictive, conservative, or simply old-fashioned. Here I want to assert limits of the kind and extent of musical conclusions that we can expect to draw from the available data, but also to explore the kinds of ideas that we can entertain without fear of restriction by those same data.Gurney as well as West report with approval a new reading proposed by Th. J. H. Krispijn. There is more to be said about this reading and about its effect on our understanding of ancient Near Eastern music. Krispijn's new reading is for the text UET VII 74, for which Gurney now gives an updated transliteration (p. 102). I reproduce here Gurney's paradigms for the instructions in Chapters I (ll. 1–12) and II (ll. 13–20) of UET VII 74.(1–12) If the sammu is (tuned as) X and the (interval) Y is not clear, you tighten the string N and then Y will be clear. Tightening.(13–20) If the sammu is (tuned as) X and you have played an (unclear) interval Y, you loosen the string N and the sammu will be (in the tuning) Z. [Loosening].When first interpreting this text twenty-five years ago, it was assumed that Chapter I involved loosening the strings one by one, thus shifting the whole tuning gradually downwards; and in Chapter II, tightening the strings one by one, with the reverse effect. As we then read the text, it did not specify tightening or loosening, and so the choice was arbitrary. Gurney (p. 102) blames the choice on the assumption that the text referred to the harp, whose longest and lowest string was identified as “front”, therefore (according to Nabnītu XXXII) the “first”.