... on these results is discussed. One considers afterward the modal superposition method to analyze site effects from a quantitative point of view (effective modal mass). For a translational excitation (assumption of rigid base motion) and a frequency range acceptable for such vibratory investigations, a strong...

... the applicability of modal superposition as a means of simulating ground motion of possible engineering interest. Modal solutions of flat earth problems are desirable because of the modest cost involved and the versatility of the method in simulating extended sources and anelastic damping. P-SV and SH motions can...

...Mahir Çetin; Erdal Şafak The common approach to develop analytical models of multi-story buildings from their vibration records is to match the modal properties identified from the records. However, the models developed by matching only the modal properties do not necessarily represent the real...

..., in the design or retrofit of structures. However, a natural source of energy dissipation is the interaction between a structure, its foundation, and the supporting soil medium. To account for this frequency-dependent energy dissipation in dynamic analysis based on modal superposition, relatively simple...

...Xiaofei Chen Abstract In this article, we present a new formulation of Love waves in arbitrarily irregular multilayered media by using the global generalized reflection/transmission matrices method (abbreviated to GGRTM; Chen, 1990, 1995, 1996). From the basic principle that the modal solutions...

... combination of the r.m.s, superposition and the absolute value superposition of modal maxima. A comparison is made with a previously proposed method and some comments are made on the accuracy. In a recent paper (1) R. W. Clough presents two methods for approximating the maximum earthquake response of multi...

...B. L. N. Kennett Abstract The propagation of Lg waves in complex media can be described either by means of a modal superposition scheme with numerical integration through the heterogeneity or by using ray diagrams. Rays are set off at equal horizontal intervals in a stratified zone adjacent...

... in the range of the S-wave arrival in cases 3 and 4. Harvey (1981) showed that there are three problems in the normal-mode superposition method: The properties of the present method also have to be compared with the modal superposition method of 1. spurious reflection off the cap layer; Harvey. The difference...

... ). Unimodal represents the presence of a single optimal solution within the solution domain. Multimodal indicates the existence of two or more potential optimal solutions. Composite modal structures may contain multiple distinct solutions, each with unique characteristics. The superposition of these solutions...

... of freedom systems may be calculated by the mode superposition method, in which the re- sponse of each vibration mode is evaluated separately and then the total response at any time is obtained by adding together the individual modal responses at that time. Thus the dynamic analysis is carried out in two...

... and Bouaanani (2013) , but their focus was on direct integration time-history dynamic analysis of dam-reservoir systems rather than response spectrum and modal superposition analyses. The article is organized as follows. First, the theoretical background of the proposed methods is presented considering...

...Terumi Touhei Abstract Layered solid-fluid media were analyzed using a discrete wavenumber and normal-mode superposition method, in which normal modes were obtained by finite-element method. A scalar wave equation for fluid pressure was employed in the formulation to introduce the effects of fluid...

...-wise composition based on subcurves that each describe a homogeneous pore system. Peters and Klavetter (1988) first proposed the superposition of two uni-modal pore systems to represent the hydraulic properties of fractured rock. This approach was used by Othmer et al. (1991) to describe soil...

... the response obtained by adding the absolute values of the modal responses. On the other hand, for system with a large number of degrees of freedom, the exact response approaches the r.m.s, super- position of modal responses. The method used by Clough for computing the r.m.s. error tends to mask the errors...

... by avoiding the need for calculating synthetic apparent or modal dispersion curves. Based on several synthetic and real examples with inversion results from the classical and the proposed methods, we find that correct velocity models can be retrieved through the multimodal inversion when higher modes...

.... The method is based on exact expressions for the response of the underlying half-space cast in the wavenumber-time domain, and a complete modal solution in that domain for the layers. The proposed method is highly effective and avoids the problems of the usual propagator matrix method that arise when...

... are built. Thus, each SDOF system corresponds to a vibration “mode” i with “modal” vector ϕ i (the quotation marks indicate that the application of the superposition principle is not strictly valid). The displacements u i and the inelastic resisting forces F si are supposed...

.... (1989) . Displacement approach for generalized Rayleigh waves in layered solid-fluid media , Bull. Seism. Soc. Am. 79 , 1251 - 1263 . Touhei T. (1994) . A discrete wavenumber and normal-mode superposition method for synthetic...

...-velocity scanning is applied to this multi-modal record, the resulting scanned curve will be the same as a superposition ( Fig. 3(e) ) of the two individual scanned curves ( Fig. 3(d) ) obtained from each single-mode record. In this case, however, Park et al. (2001) indicate that the superposition...