We review recent progress in applying the theory of rigidity to glassy networks and to proteins. These three dimensional systems require a generalization of Laman's theorem, which we have used to develop a technique called the Pebble Game which allows the rigid regions (containing both isostatic and overconstrained parts) and the flexible joints between them, to be found. We show that a flexibility index, which measures the local density of floppy modes, is useful in characterizing the network. A sampling of recent results is given for network glasses, where we show how the glass structure can self-organize to produce an intermediate phase that is stress-free and contains a percolating isostatic cluster. In proteins, we show how maps of the rigid regions and flexible joints, as well as maps of the flexibility index, can help to elucidate the connection between structure and function.
Probably the most significant link between research into Earth tides and seismology is connected with the first attempts to measure the Earth’s effective elasticity using these tides. In 1863 William Thomson (Lord Kelvin) published his famous paper “On the rigidity of the Earth”, which describes how these observation could determine the mean rigidity of the Earth. This current paper sets out to describe some important developments in this common area of study between seismology and earth tide research until the middle of the twentieth century.
Experimental research of precast plate-monolithic wall connection within specific system developed in Tuzla, Bosnia and Herzegovina, in 80’s named “MMS” building system, is presented. System MMS is precast — monolithic building system specially adapted for high building constructions with characteristics of repetition of specific number of similar floors. The connections of monolithic wall and precast plate are executed with a dislocation potential joints opening which provided the structure displacement under seismic load. In this way joints become available for inspection and possible reparation/rehabilitation. The aim of presented researches is to determine the degree of connection loosening (yielding). The results of experimental tests will be used for numerical modeling of connections, which will be presented in forthcoming paper.
A bicycle ( n , k )-gon is an equilateral n -gon whose k -diagonals are equal. S. Tabach-nikov proved that a regular n -gon is first-order flexible as a bicycle ( n , k )-gon if and only if there is an integer 2 ≦ r ≦ n -2 such that tan (π/ n ) tan ( kr π/ n ) = tan ( k π/ n ) tan ( r π/ n ). In the present paper, we solve this trigonometric diophantine equation. In particular, we describe the family of first order flexible regular bicycle polygons.
A dolgozat célja megmutatni azt, hogy ha egy terhelt rácsos tartó egy terheletlen csomópontjának helyzete a tervezettől kismértékben eltér (pl. kivitelezési pontatlanságok miatt), akkor azon rudak halmaza, melyekben az említett eltérés hatására megváltozik a rúderő, pusztán a tartó topológiájának ismeretében meghatározható. A [Tóth, Domokos, Gáspár 2009]-ben a statikailag határozott esetre mutattuk meg az említett állítást, a jelen cikkben – az erőmódszer gondolatmenetére építve – általánosítjuk azt a határozatlan tartókra is kiterjesztve. A cikk intuitív leírást közöl az eljárás alapjául szolgáló ötletről, de az eljárás matematikai bizonyítása további cikknek – melynek előzetes verzióját lásd a [Jordán, Domokos, Tóth 2011]-ben – tárgya.
Filomat 2009 23 108 116 Velimirović Lj., Rančić S., Zlatanović M. Rigidity and flexibility
form of buildings which have a safe behavior under the effect of the seismic action which depends on several factors: rigidity, an adequate lateral resistance, ductility as well as simple and regular configurations [ 1 ]. There is much less risk to
the epoxycyclopentenyl ring system. The cured epoxy DCPD-based resins possess excellent rigidity, mechanical strength, high thermal stability, electrical properties after curing, high dimensional stability, and high resistant to UV light. They are
order to complete the study of the curing kinetics of the chestnut shell tannin adhesives, the DMA technique was used to evaluate the mechanical curing rate, which characterizes the cure in terms of the rate of rigidity development, while DSC evaluates