Sectional curvature

Part 1 of ebook "Seismic design aids for nonlinear analysis of reinforced concrete structures" provides readers with contents including: Chapter 1 - Axial force–bending moment yield interaction; Chapter 2 - Moment-curvature relationship for RC sections; Chapter 3 - Moment-rotation relationship for RC beams;...

130p dongmelo 21-05-2024 6 3   Download

This paper presents an experimental programme conducted on a number of six reinforced concrete (RC) beams in order to investigate the developments of strain and stress, moment-curvature relationship, failure mode and the ultimate strength on normal sections (USoNS) of this type of basic structural element.

9p vinobita2711 31-05-2019 27 1   Download

We obtain a differential equation with 2 boundary conditions for a relaxed elastic line in a Riemannian manifold. This differential equation, which is found with respect to constant sectional curvature G, geodesic curvature κ, and 2 boundary conditions, gives a more direct and more geometric approach to questions concerning a relaxed elastic line in a Riemannian manifold.

7p danhdanh27 07-01-2019 22 2   Download

In this article, we establish an inequality between the sectional curvature function K and the shape operator AH at the mean curvature vector for slant submanifolds in generalized complex space forms. Also a sharp relationship between the k-Ricci curvature and the shape operator AH is proved.

15p danhdanh27 07-01-2019 19 2   Download

In the case of negative sectional curvature, we obtain some monotonicity formulas which support the conjecture that after normalization, for initial metrics on closed 3-manifolds with negative sectional curvature, the solution exists for all time and converges to a hyperbolic metric. This conjecture is still open at the present time.

10p danhdanh27 07-01-2019 12 2   Download

In this paper, the geometry of F-invariant submanifolds of a Kaehlerian product manifold is studied. The fundamental properties of these submanifolds are investigated such as pseudo umbilical, curvature invariant, totally geodesic, mixed geodesic submanifold and locally decomposable Riemannian product manifold.

15p danhdanh27 07-01-2019 15 1   Download

R Huang worked the p-elastic in a Riemannian manifold with constant sectional curvature. In this work, we solve the Euler-Lagrange equation by quadrature and study the Frenet equation of the p-elastica by using the Killing field in the three dimensional Lorentzian space forms.

9p danhdanh27 07-01-2019 25 1   Download

In this article, we establish inequalities between the Ricci curvature and the squared mean curvature, and also between the k-Ricci curvature and the scalar curvature for a slant, semi-slant and bi-slant submanifold in a cosymplectic space form of constant ϕ- sectional curvature with arbitrary codimension.

14p danhdanh27 07-01-2019 11 1   Download

In this paper we have obtained a general existence as well as uniqueness theorem for slant immersions into a Kenmotsu-space form. The purpose of the present paper is to establish a general existence and uniqueness theorem for slant immersions in Kenmotsu-space forms.

17p danhdanh27 07-01-2019 20 1   Download

In the paper, we study biharmonic legendre curves in S−space forms. We find curvature characterizations of these special curves in 4 cases. The paper is organized as follows: In section 2, we give a brief introduction about S−space forms. In section 3, we give the main results of the study.

8p tuongvidanh 06-01-2019 20 2   Download

In this paper, we prove B. Y. Chen inequalities for submanifolds of a Riemannian manifold of quasiconstant curvature, i.e., relations between the mean curvature, scalar and sectional curvatures, Ricci curvatures and the sectional curvature of the ambient space. The equality cases are considered.

9p tuongvidanh 06-01-2019 22 2   Download

There are very few examples of Riemannian manifolds with positive sectional curvature known. In fact in dimensions above 24 all known examples are diffeomorphic to locally rank one symmetric spaces. We give a partial explanation of this phenomenon by showing that a positively curved, simply connected, compact manifold (M, g) is up to homotopy given by a rank one symmetric space, provided that its isometry group Iso(M, g) is large. More precisely we prove first that if dim(Iso(M, g)) ≥ 2 dim(M ) − 6, then M is tangentially homotopically equivalent to a rank one symmetric space or M...

63p noel_noel 17-01-2013 54 5   Download

Any sphere S n admits a metric of constant sectional curvature. These canonical metrics are homogeneous and Einstein, that is the Ricci curvature is a constant multiple of the metric. The spheres S 4m+3 , m 1, are known to have another Sp(m + 1)-homogeneous Einstein metric discovered by Jensen [Jen73]. In addition, S 15 has a third Spin(9)-invariant homogeneous Einstein metric discovered by Bourguignon and Karcher [BK78]. In 1982 Ziller proved that these are the only homogeneous Einstein metrics on spheres [Zil82]. ...

25p noel_noel 17-01-2013 49 4   Download

Two-axle vehicles without trailer Low speed or kinematic steering is, as already stated, defined as the motion of a wheeled vehicle determined by pure rolling1 of the wheels. The velocities of the centres of all the wheels lie in their midplane, that is the sideslip angles αi are vanishingly small. In these conditions, the wheels cannot exert any cornering force to balance the centrifugal force due to the curvature of the path. Kinematic steering is possible only if the velocity is vanishingly small.

102p hiruscar 19-10-2010 45 6   Download

The essential constituent of a conformal array is curvature. Authorities disagree on whether the array must be part of a curved metallic structure; in this chapter curvature alone is sufficient. Arrays of one or more concentric rings of elements, here called “ring arrays,” are treated first. The term “circular array” is not used, as it often means a planar array of circular perimeter. The following sections deal with arrays on curved metallic bodies. Most simple is the cylinder; Section 11.3 treats cylindrical arrays with elements around the full circumference....

69p huggoo 23-08-2010 79 12   Download