The Influence of Static Response of Super Tall Building Mega-Frame Structure Caused by Changes of Frame Rigidities

The superstructure and its foundation of a super tall building mega-frame structure are simplified equivalently and continuously to a stiffened-thin-wall tube on semi-infinite elastic subgrade. And the influences of static response on super tall building mega-frame structure caused by changes of frame rigidity are computed and analyzed with the three-dimensional model by semi-analytical approach based on ODE(Ordinary Differential Equation) Solver, considering the interactions of subgrade, foundation and superstructure. Then some valuable conclusions are obtained through analyzing the reasonable results of the numerical example.

Structural Analysis of High-End Server Computer Frames Under Earthquake Loading

This paper reports the mechanical design, structural analysis, and experimental correlation of bracing concepts for high-end computer servers subjected to loads simulating earthquake conditions. The development and evaluation of these stiffening alternatives follows a step-by-step process of finite element analysis coupled with parallel experimental testing. The numerical model is derived from the simplified CAD geometry of an existing server frame. An analysis of this frame model is subjected to a load environment similar to those endured under actual horizontal table vibration tests. The result of this series of analyses is a design study examining how a range of bracing designs affects the global frame rigidity. This design study builds toward the objective of constructing a verified model of the server frame and components that will lead to a guideline for implementing stiffener designs on high-end server systems.

Contributions of the USNO to the Optical Reference Frame

A good, working definition of what is required in a celestial reference frame is that it must provide observable fiducial points on the Celestial Sphere with internally consistent positions that are referred to coordinate axes of known direction. In reality, this statement gives the goals in the reverse order from that in which each must be achieved, the definition of the axes, or zero points of the system give orientation to the observationally defined set of primary objects whose coordinate relation to each other must give the frame rigidity. Finally, the primary objects are generally too sparse to define the frame within areas of less than tens of square degrees, and so additional objects must be related to the frame to increase the density. This last step is required to make the frame useful for most observational applications.