Shuichi Asayama

• Dr. Engineering
• Professor (Full) at Tokyo Denki University

Authors described a fractal lattice dome generated by seven contraction mapings in 3D space onto an original one. This paper reveals mathematical condition that the seven small domes as subsets generated by contraction mapping never overlap to keep one to one function (Barnsley, M. F [1]). The useful formula to calculate Hausdorff dimension is also...

This paper aims to explore the scope of applying the concept of fractal geometry in the field of architecture and construction. There are mainly two different types of fractals – self-similar fractal and random fractal. In this paper, both types of fractals are used to design a nature-inspired architectural structure with the strategy of exploring...

The modern structure is based on Euclidean geometry. If Fractal geometry can be applied to artificial structures without losing mechanical rationality, it will extend possibility of architectural form and space toward those in nature. In this paper, authors describe a concept of the fractal structure, introducing a fractal truss and a layered arch...

This paper describes mechanical characteristics of a spatial structure with geometry from wind ripple and sand dune when subjected to vertical load. The geometry is generated according to the approximate modeling based on salutation and creep in height field. Three lattice spatial structures with bracing based on wind ripple, sand dune and combinat...

The objective of this paper is to design architectural structures inspired by the geometry of nature, known as ‘fractals’, as a venture for exploring a possibility of new architectural forms that we may have rarely experienced before, but already noticed in nature such as the botany and mountain. Two examples of natural objects having different fra...

This paper describes a structural morphogenesis using wavy forms generated by the ocean wave theory. Generally an initial form for optimization is chosen from simple geometries such as cube and globe but authors have been engaged in morphogenesis using geometries of nature such as a tree and landform (Mae et al., 2004; Nakamura and Asayama, 2009)....

This paper describes a couple of new truss structures based on fractal geometry. One is the famous Sierpinski Gasket and another is a fractal triangle derived by means of applying a process forming leaves of a cedar tree using M. F. Barnsley’s contraction mapping theory. Therefore a pair of x-y coordinates of an arbitrary nodal point on the structu...

This paper describes the static characteristics of a layered arch with fractal geometric form against wind loading. Wind tunnel test is conducted to acquire the wind force coefficient. It can be thought separated flow is found near the top of the structure through the distribution obtained experimentally as a whole. Subsequently analytical results...

This paper describes the mathematical characteristics of a layered arch with fractal geometric form and its application to structure and architectural design. Fractal dimension of the structure is acquired from geometric formulae derived here and its value ranges from 1.0 to 1.24. Subsequently structural data for frame analysis are generated automa...

This paper describes fundamental issues on responses of the new type of structures governed by nonlinear equations using one mass system with nonlinear histeretic curves. Differential equations with terms on nonlinear restoring forces idealized by hard and soft springs were solved directly by Runge-Kutta method and the numerical results were compar...

A fractal set for layered arch structure can be derived geometrically using contraction mapping. Theoretical method how to acquire the Hausdorff dimension is described and the numerical results are presented. IFS code is also presented, which defines strict configuration of the fractal arch. It makes automated data generation for frame analysis pos...

This paper describes the geometric characteristics of fractal triangles constituting truss structures. Next, geometric images of them are generated on a graphic display using IFS code and chaos algorithm. They are converted into data files of a 3D CAD system which are normally described by Euclidian geometry and then, more realistic images of archi...

Spatial variation of ground motion in a site for building with long configuration was investigated by means of seismograph array at a campus of Hatoyama-machi in Saitama Prefecture. The result shows that some earthquake records can be thought appoximately traveling shear waves with components lower than 5Hz though those in higher frequency domain a...

: This paper treats a basic study on a methodology of large reduction of the huge stiffness matrix equation with many unknowns for application on very high speed supercomputer or connection machines. Until recently the substructured method according to the Neumann-type single processing has been used for the above purpose, whereas the method descri...

Although a considerable amount of studies have been carried out for many years related to response of building of long and huge configuration in plan, none of those studies gives theoretical explanation clearly on actual dynamic behaviors. In this paper, authors describe methdology of modelling of this type of building using an actual structure and...

Since the end of 1960's, several experimental studies have been tried concerning response of building of long and huge configuration in plan based upon earthquake observations and microtremor measurements. Some of these studies described that high frequency components of the earthquake records on the base of the building were decreased when compari...

In this paper a method of forming any structural stiffness matrix corresponding with a remarkably reduced number of unknowns for structural horizontal vibration to apply to earthquake response is presented.Although today it has become possible to treat any problem related to more vibratory unknowns than ever in relation with the rapid advancement o...

This paper treats theoretical derivation ofa numerical procedure and its accuracy concerning nonlinear response analysis of buiding subjected to spacially variant ground motion. And furthermore dynamic characteristics of simplified parallel 3-mass system connected by horizontal slab springs that represents the building of long and huge configuratio...

This paper presents a nonlinear hysteretic model of an isolator that reproduces real experimental curve with hardening and energy absorption and discusses its nonperiodic response behaviors and stability. First a mathematical nonlinear equation governing one mass system is given and two types of hysteretic curves adopting the polynomial and cubic f...

This paper describes nonlinear response of base isolated structure subjected to ground motion with large amplitude from the viewpoint of chaotic dynamics. Since the isolators sustaining the superstructure show hardening characteristics in hysteretic curves under these circumstances, the dynamic system should be expressed mathematically by a nonline...