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The purpose of this paper is to study the effect of mean stress and stress amplitude on the asymmetric cyclic deformation behavior of SA333 Gr-6 C-Mn steel. Such type of loading may arise during the service period because of the load fluctuations, thermal gradients and sudden loading like seismic events. Tests were also carried out at different temperatures to understand the effect of it on sensitiveness of the materials deformation behavior.

Cylindrical specimen of 8-mm gauge diameter and 15-mm gauge length was fabricated from the pipe section along its axis. Stress controlled ratcheting tests were carried out by using triangular waveform for cyclic loading. The strain accumulations were measured using 12.5-mm gauge length extensometer. Ratcheting tests were carried out at fixed stress amplitude of 400 MPa and mean stress varying from 0 to 75 MPa, whereas at the fixed mean stress of 100 MPa and stress amplitude varies from 300 to 400 MPa at 300°C. To study the effect of temperature on ratcheting behavior, tests were carried out at a load of 100 MPa mean stress and 350 MPa stress amplitude, with a varying temperature between room temperature and 350°C. The stress rate of 115 MPas-1 was kept constant for all the tests.

Increase in mean stress and stress amplitude, ratcheting strain and plastic strain amplitude increases, whereas ratcheting life decreases. With an increase in temperature, ratcheting life increases and strain accumulation decreases up to 300°C, whereas on further increase in temperature, strain accumulation increases with reduction in ratcheting life. Minimum ratcheting rate was observed at 250°C and 300°C. The dynamic strain aging (DSA) phenomena lead to the hardening of the material. The investigated steel shows DSA temperature regime lies between 250°C and 300°C. The failure modes at 250°C and 300°C temperature was transgranular, whereas at 350°C complete ductile.

The stress rate and loading condition may vary to study the ratcheting behavior.

From this study, the critical cyclic load may be determined. The DSA temperature regime of this material is determined at this stress rate. This could help to evaluate the cyclic deformation behavior of the material with temperature changes.

In this investigation, the DSA temperature regime has been determined where maximum ratcheting life, minimum strain accumulation and ratcheting rate were observed. The critical load where the minimum life of the material occurred at elevated temperature is 100 MPa mean stress and 400 MPa stress amplitude.

The purpose of this research is to study the effect of high temperature on concrete columns which are considered the most important part of the concrete structure. Glass fibres were used to study the effect of heat on them as well as on the properties of reinforcing steel and concrete.

High tensile stress may develop at the tension zone of the column section when the column is exposed to an axial compressive load with a relatively high eccentricity. Since fibre bars have a higher tensile strength than steel bars, they can be used in the tension zone of hybrid reinforced concrete columns to resist tensile stress, while steel bars can be used in the compression zone to resist compressive stress. However, as documented in prior research studies and advised by standards and codes, the mechanical qualities of concrete, steel and fibre bars are considerably damaged when hybrid columns are exposed to high temperatures.

When the fire temperature rises, the ultimate load value of the reinforced concrete column decreases. Also, steel bar reinforcing is more efficient than glass fibre bars in resisting high temperatures. The rate decrease in the strength of reinforced concrete columns to applied load on it decreases with the rise of the temperature to which the specimen was exposed during the burning period.

The experimental and numerical work includes a study of the effect of a fire furnace on the behaviour of hybrid R.C. columns. Three types of reinforcement were used steel bars only, G.F.R.P bars only and hybrid (steel and G.F.R.P) bars. These columns specimens were cast and divided into three groups according to the details of reinforcement, the effect of fire temperature and according to the eccentricity ratio. Two types of hybrid are used in this work. Fourteen R.C. columns were casted and divided into, 4 specimens not burn and 10 specimens burn at temperatures 300, 500 and 700.

Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines; reluctance motors; PM motors; transformers and reactors; and special problems and applications. Debates all of these in great detail and itemizes each with greater in‐depth discussion of the various technical applications and areas. Concludes that the recommendations made should be adhered to.

This paper is contributed to find the minimal mass prismatic tensegrity structures.

In the stable state of the structure with any given external force, the internal forces of the structure members are taken as the critical force to calculate the cross-sectional area, and the total mass of the structure can be obtained. Firstly, the mathematical model of prismatic tensegrity was built. Secondly, the stability of the tensegrity was analyzed based on the force equilibrium of one node, the force density relationship of elements was obtained. The deformation of p-bar tensegrity prism unit was studied with the same mass. The force of the structure under external force was analyzed.

(1) The length of bar and the structural radius are almost invariant, and the mechanical properties of 3-bar tensegrity prism is more outstanding; (2) theoretically, the mass of the structure is minimal while the projection of bar passes the center of the circle. Under the circumstances, the force of diagonal cable is 0 N, the vertical force component of bar cancels the axial external force.

(1) By analyzing the deformation of p-bar tensegrity prism with the same mass, the length of bar and the structural radius are proved be almost invariant and the mechanical properties of 3-bar tensegrity prism is more outstanding; (2) theoretically, the mass of the structure is minimal while the projection of bar passes the center of the circle. Under the circumstances, the force of diagonal cable is 0 N, the vertical force component of bar cancels the axial external force.

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the theoretical as well as practical points of view. The range of applications of FEMs in this area is wide and cannot be presented in a single paper; therefore aims to give the reader an encyclopaedic view on the subject. The bibliography at the end of the paper contains 2,025 references to papers, conference proceedings and theses/dissertations dealing with the analysis of beams, columns, rods, bars, cables, discs, blades, shafts, membranes, plates and shells that were published in 1992‐1995.

Presents over sixty abstracts summarising the 1999 Employment Research Unit annual conference held at the University of Cardiff. Explores the multiple impacts of globalization on work and employment in contemporary organizations. Covers the human resource management implications of organizational responses to globalization. Examines the theoretical, methodological, empirical and comparative issues pertaining to competitiveness and the management of human resources, the impact of organisational strategies and international production on the workplace, the organization of labour markets, human resource development, cultural change in organisations, trade union responses, and trans‐national corporations. Cites many case studies showing how globalization has brought a lot of opportunities together with much change both to the employee and the employer. Considers the threats to existing cultures, structures and systems.

An analytical rheological‐dynamical visco‐elastic solution of one‐dimensional longitudinal continuous vibration of bars has been developed and used to evaluate the validity of the classical analytical elastic solutions. As it is well known, the resonance occurs only in the continuous or singledegree‐of‐freedom ideal elastic system when the excitation frequency ωP is equal to the one of the natural frequency of the bar. However, owing to the visco‐elastic nature of materials and frequency dependence of the damping factor it is useful to consider separately the situations arising when the is positive (system is stable) and when it is negative. Negative damping factor means that the complementary solution of the response would not die away (system is unstable because of the factor e). Rheologic behavior of the bar can be characterized by one parameter, i.e. dynamic time of retardation TK D=1/ω, like in a single‐degree‐of‐freedom spring mass system. RDA model has the same phase angle as a simple single‐degree‐of‐freedom spring mass system with damping in the steady state vibration and from that the damping factor is obtained. This paper provides description of the dynamic magnification factor and the transmissibility of several metallic materials using RDA similitude and could be concluded that an ideally effective antivibration mount material should satisfy at least two requirements: first, it should posses a relatively large damping factor; and second, it should possess a damping factor that either remains constant or decreases only slowly with frequency.

The track impedance is one of the most important parameters in designing the track circuit which is widely used in the railway signal control system to detect the presence of a train. This paper aims to calculate the ballastless track impedance by taking account of the influence of reinforcement bars.

This paper proposes a two-step decomposition approach to calculate the ballastless track impedance. The basic idea is evaluating the track impedance without the reinforcement bars by using two-dimensional (2D) finite element method (FEM), and the incremental impedance, because of the reinforcement bar, is calculated by the partial element equivalent circuit (PEEC) method.

The numerical examples show that the proposed approach can guarantee the accuracy and largely reduce the computing time, at least 20 times, compared with the direct three-dimensional (3D) FEM method.

The study provides a fast approach to calculate the ballastless track impedance. However, compared with the 3D FEM method, the results are less accurate because of the approximation and assumption adopted in the method. A future study should pay more attention to improve accuracy of the model.

A fast approach is proposed to calculate the ballastless track impedance taking account of the influence of the reinforcement bars. The computing time can be largely reduced by using the method. With the proposed approach, the influence of insulation of the reinforcement bars on track impedance can be analyzed.

Aarhus Kommunes Biblioteker (Teknisk Bibliotek), Ingerslevs Plads 7, Aarhus, Denmark. Representative: V. NEDERGAARD PEDERSEN (Librarian).

Investigates the differences in protocols between arbitral tribunals and courts, with particular emphasis on US, Greek and English law. Gives examples of each country and its way of using the law in specific circumstances, and shows the variations therein. Sums up that arbitration is much the better way to gok as it avoids delays and expenses, plus the vexation/frustration of normal litigation. Concludes that the US and Greek constitutions and common law tradition in England appear to allow involved parties to choose their own judge, who can thus be an arbitrator. Discusses e‐commerce and speculates on this for the future.