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A damage-controlled structure is defined as a combination of structural systems and energy transformation devices that are integrated in such a way that damage due to a major loading is restricted to a specific set of elements that can be readily repaired. This paper describes a preliminary design methodology for building structures subjected to seismic loading, and presents a comprehensive set of numerical simulations illustrating the response of typical structures designed according to this methodology. The proposed design considers the structure to consist of two independent structural systems that work together to satisfy a design requirement on the deformation. The first system functions as the principal load-carrying mechanism for vertical and lateral service loads, while the second structure's role is to dissipate and absorb the energy introduced by significant ground shaking. The key design parameters are the elastic stiffness distribution of the primary system, and the damping characteristics of the secondary system. An optimal evaluation of these parameters is presented for a specific choice of material strengths. The data show that the damage control design paradigm generates very good estimates for preliminary design in this case.

From our previous studies, it has been found that the Fe-Pb-O granular films which have been adequately annealed exhibit an enhanced tunneling magnetoresistance effect (TMR). The TMR effect is about 10% at room temperature, which can be claimed as the maximum value ever detected so far. In this report the TMR effect of Fe-Pb-O granular films from different annealing time have been investigated. The Mossbauer spectrometer was used to collect the information of Fe magnetic microstructure. It has been found that the tunneling barrier from the magnetic compound formed between a-[Fe.sup.2][O.sub.3] and PbO plays an important role in obtaining large TMR effect. And the non-magnetic Fe-Pb-O compounds which exist on the surface of iron granules as a thin layer and grow with annealing time seem to decrease TMR effect.

The magneto-transport properties of the granular [Fe.sub.0.5][([Al.sub.20][O.sub.3]).sub.0.5] solids with various film thickness have been investigated. The temperature dependence of the resistivity shows that all samples follow a tunneling type equation [Rho](T) =[Rho]exp[([T.sub.0]/T).sup.1/[Alpha]] with [Rho] [approximately equal to] 0.0 [similar to] 1 [ohms]cm at 300K and [Alpha]=2. The results of magneto-resistance at 300K indicate that the value is about 4.5% for thick films. It increases slowly with decreasing film thickness. At about 150nm, a peak value of TMR is found, which is determined to be 5%. Then TMR drops sharply with further reducing film thickness. It becomes only 3% at t=20nm. At low temperatures, the TMR effect becomes larger and shows similar thickness dependence. However, the values of [T.sub.0] that relate to the geometry of the tunneling barrier show behavior of opposite thickness dependence. A small [T.sub.0] is associated with a large TMR effect. In this report, the correlation of the film microstructure and the TMR effect are discussed in details.