Equivalent static method

In the case of simple structures it is possible to use equivalent static methods to those suggested by national standards in general, however, in many cases a dynamic analysis (also mentioned in... 

In the equivalent static method, first the base shear is calculated, which is then distributed over the height of the building as specified by the pertinent seismic code. In the response spectmm analysis, for a given direction of acceleration, the... 

Fig. 32 Deformed shape of prototype building from equivalent static method - transverse direction...

Site subsoil class Equivalent static method Dynamic analyses methods ... 

The design criteria for land units may be in accordance with local building codes using equivalent static design methods. 

The equivalent static design procedure described above is widely used in the petrochemical industry. Occasionally, the results of a equivalent static design results in a foundation which is impractical, or too costly. In this situation, the dynamic analysis method can be used. A dynamic analysis takes into account the inertia of the foundation mass in resisting the load, and will generally yield a more economical design. The procedure is described in detail in 1M 5-856 (volume 4) and TR 492L... 

In the Equivalent Static Design Method, foundations are typically designed for the peak reactions obtained from the superstructure dynamic analysis. These reactions are treated as static loads, disregarding any time phase relationship. The basis for equivalent static design is discussed in 7M 5-856. 

The following design represents one way of handling a foundation for this situation. Other design options might include a combination of vertical piles and passive resistance. The Equivalent-Static Design Method will be used as described in section 7.7.1. 

This thin-film-composite membrane has been found to have appreciable resistance to degradation by chlorine in the feed-water. Figure 2 illustrates the effect of chlorine in tap water at different pH values. Chlorine (100 ppm) was added to the tap water in the form of sodium hypochlorite (two equivalents of hypochlorite ion per stated equivalent of chlorine). Membrane exposure to chlorine was by the so-called "static" method, in which membrane specimens were immersed in the aqueous media inside closed, dark glass jars for known periods. Specimens were then removed and tested in a reverse osmosis loop under seawater test conditions. At alkaline pH values, the FT-30 membrane showed effects of chlorine attack within four to five days. In acidic solutions (pH 1 and 5), chlorine attack was far slower. Only a one to two percent decline in salt rejection was noted, for example, after 20 days exposure to 100 ppm chlorine in water at pH 5. The FT-30 tests at pH 1 were necessarily terminated after the fourth day of exposure because the microporous polysul-fone substrate had itself become totally embrittled by chlorine attack. 

One of the most useful static methods of microscopic chemical kinetics is based on the definition of the reaction path as introduced by Fukui. This method offers information on reactions in terms of the intrinsic reaction coordinate (62,144). A theoretical analysis of the minimum energy path was given in Section III,B. Fukui s definition is equivalent to Eq. (34). 

Here ns is the amount of substance of stationary liquid, pi is the saturated vapour pressure of the solute at temperature r. Bag is the mixture virial coefficient for solute 4- carrier gas interaction, Bcc is the virial coefficient of the carrier gas, Fjj is the partial molar volume of the solute at infinite dilution in the solvent, is the molar volume of pure liquid A, and pi and po are the column inlet and outlet pressures. The chemical potential at infinite dilution can be calculated by measuring the retention volume of an infinitely small sample for various inlet and outlet pressures and extrapolation to zero pressure drop across the column. Everett and Stoddart proposed using equation (33) to determine the mixture second virial coefficients. The precision in Bag from this method is nearly equivalent to the best static methods. The assumptions required to derive the above equation have been examined by a number of authors. - ... 

Simplified methods, such as the equivalent static, should be restricted to use for assessment purposes. 

In Nikelly s opinion dynamically coated SCOT columns are almost equivalent to those made by the static method in terms of efficiency and capacity. 

Equivalent Static Elastic Lateral Force Method... 

The equivalent static lateral force method is a simplified technique to substitute the effect of dynamic loading of an expected earthquake by a static force distributed laterally on a stmcture for design purposes. The total applied seismic force V is generally evaluated in two horizontal directions parallel to the main axes of the building (Fig. 1). It assumes that the budding responds in its fundamental lateral mode. For this to be true, the building must be low rise and must be fairly symmetric to avoid torsional movement under ground motions. The stmcture must be able to resist effects caused by seismic forces in either direction, but not in both directions simultaneously. 

The simplest way to do so is using the equivalent static lateral force method, even though its uses are limited by various conditions, related to the site and the stmcture itself and which are acknowledged and detailed below. Within this method, a seismic coefficient is applied to the mass of the stmcture to produce the lateral force that is approximately equivalent in effect to the dynamic loading of the expected earthquake. 

The equivalent static lateral force method is a simplified technique to substitute the effect of dynamic loading of an expected earthquake by a static force distributed laterally on a structure for design purposes. The total applied seismic force V is generally evaluated in two horizontal directions parallel to the main axes of the building. 

Calculate the demanded slip force and size the in-line brace by employing simplified methods (e.g., the equivalent static force procedure). Then, the demanded peak interstorey drift (e.g. linear dynamic analysis methods) should be evaluated. 

WSRC shall meet the following acceptance criteria for piping qualified by the equivalent static load method. 

The acceptance criteria from the appropriate sections of the Equipment Qualified bv Dynamic Analysis section shall apply to the equipment qualified by the equivalent static load method (a special case of the dynamic analysis method), as supplemented by the following ... 

The methods used to show acceptability of outliers shall be identified. The acceptable methods include response spectrum analysis, equivalent static analysis, or testing. 

RPA, and CPHF. Time-dependent Hartree-Fock (TDFIF) is the Flartree-Fock approximation for the time-dependent Schrodinger equation. CPFIF stands for coupled perturbed Flartree-Fock. The random-phase approximation (RPA) is also an equivalent formulation. There have also been time-dependent MCSCF formulations using the time-dependent gauge invariant approach (TDGI) that is equivalent to multiconfiguration RPA. All of the time-dependent methods go to the static calculation results in the v = 0 limit. 

---