let (m,g ) be a compact immersed hypersurface of (rn+1,) , λ1 the first nonzeroeigenvalue, α the mean curvature, ρ the support function, a the shape operator, vol (m ) the volume of m,and s the scalar curvature of m. in this paper, we established some eigenvalue inequalities and proved theabove.1) 1 2 2 2 2m ma dv dvn∫ ρ ≥ ∫ α ρ ,2)( )2 2 1 2m 1 mdv s dvn nα ρ ≥ ρ∫ − ∫ ,3) if the scalar curvatu...

this paper presents the results of analytical studies concerning the flexuralstrengthening of reinforced concrete beams by external bonding of high-strength lightweightcarbon fiber reinforced plastic (cfrp) plates to tension face of the beam. three groups of beamswere tested analytically and compared with existing experimental results. results of the numericalanalyses showed that, although addi...

the present research is concerned with the determination of ductility, over-strength and response modification factors of coupled steel shear wall frames. three structural models with various numbers of stories, bay width and coupling beam height were analyzed using static pushover and incremental nonlinear dynamic analyses. the ductility, over-strength and response modification factors for the...

Recently, we have used the symmetric bracket of vector fields, and developed the notion of the symmetric derivation. Using this machinery, we have defined the concept of symmetric curvature. This concept is natural and is related to the notions divergence and Laplacian of vector fields. This concept is also related to the derivations on the algebra of symmetric forms which has been discu...

Using a uniaxial localization model, it is shown that parallel elasticrcstf!1int increases ductility, while an increase in support flexibility or length ofspecimen reduces ductility. Statistical macroscopic nonhomogeneity of the specimen ismodeled by a system of uniaxial parallel elements of random properties following thenormal distribution. The stability analysis and Monte Car...

Aluminum alloys with nanocrystalline (NC) and ultrafine grain (UFG) size are of interest because of their strengths that are typically 30 pct greater than conventionally processed alloys of the same composition. In this study, UFG AA 5083 plate was prepared by quasi-isostatic (QI) forging of cryomilled powder, and the microstructure and mechanical behavior was investigated and compared with the...

Damage evolution during low cycle fatigue, creep, and their interaction behavior is actually a ductility exhaustion process in response to cyclic and static creep. In this article, a novel viscosity-based model for low cycle fatigue creep life prediction is presented in an attempt to condition viscosity-based approaches for general use in isothermal and thermo-mechanical loading. In this model,...

In this paper, the authors summarize the results of a parametric study devoted to evaluate the seismic behavior of low to medium rise regular special moment-resisting steel frames with hysteretic energy dissipation devices mounted on chevron steel bracing. For that purpose, 270 different building models were designed considering typical story heights and bay widths used in Mexican practice. The...

Aluminum Matrix composites (AMCs) are light weight, high-strength materials with potential application in areas such as automobile, aerospace, defence, engineering and other industries. AMCs are projected to significantly reduce the overall weight of the vehicles and aircraft while maintaining satisfactory structural strength. Reinforcement of micron or nano-sized range particles with aluminium...