Abstract A simple method is proposed to model the open cracked beam structures. In this method, crack is modeled as a beam element. Hence cracked beam can be assumed to be a beam with stepped cross sections, and problem of determining natural frequency and mode shape of cracked beam, can be solved as determining these characteristics for a beam with different length and cross section. With this...

In this research, residual strength and stress concentration factor of laminated composites with a circular open hole are studied analytically, numerically and experimentally. The numerical study was carried out using the finite element method. Moreover an analytical study was carried out with developing of point stress criterion. Mechanical testing was performed to determine the un-notched ten...

Let us quickly recall the definitions of the terms which are used in the statement of Theorem 1, and which will be used throughout this paper. Let X be a topological space. A collection <R of subsets of X is called open (resp. closed) if every element of "R. is open (resp. closed) in X. A covering of X is a collection of subsets of X whose union is X; observe that in this paper a covering need ...

A numerical prediction model is developed to quantify vibrations and re-radiated noise due to underground railways. A coupled FE-BE model is used to compute the incident ground vibrations due to the passage of a train in the tunnel. This source model accounts for three dimensional dynamic interaction between the track, tunnel and soil. The incident wave field is used to solve the dynamic soil-s...

Open Access to particle physics literature does not sound particularly new or exciting, since particle physicists have been reading preprints for decades, and arXiv.org for 15 years. However new movements in Europe are attempting to make the peer-reviewed literature of the field fully Open Access. This is not a new movement, nor is it restricted to this field. However, given the field’s history...

The vibration pattern of a rotor system reflects the mechanical parameter changes in the system. Hence, the use of vibration monitoring is considered as a possible means of detecting the presence and growth of the cracks. In this paper, a pattern search based method for shaft crack detection is proposed and described which formulates the shaft crack detection as an optimization problem by means...

this paper is the second of a two part series. in this part, we prove, using the description of simples obtained in part i, that the variety $mathbf{rdqdstsh_1}$ of regular dually quasi-de morgan stone semi-heyting algebras of level 1 is the join of the variety generated by the twenty 3-element $mathbf{rdqdstsh_1}$-chains and the variety of dually quasi-de morgan boolean semi-heyting algebras--...