A modelling technique for calculating stress intensity factors for structures reinforced by bonded straps. Part II: Validation

In this second part of the two-part paper validation of the 2D FE modelling technique described in the first part is presented for a range of test configurations. Each mechanism that influences crack growth behaviour of strap reinforced structures is modelled for different substrate geometries, strap materials and dimensions in order to test the accuracy and robustness of the methodology. First, calculated through-thickness strain energy release rate distribution is compared with the result of a 3D FE model to validate this 2D model. Second, calculated disbond areas, thermal residual stresses and their redistribution with crack propagation are validated against experimental measurements. Third, influence of geometric nonlinearity and the need to use the alternate analysis method described in part I are demonstrated by examples, and errors generated by not following this analysis rule are given. Finally, using the 2D model calculated stress intensity factors, fatigue crack growth rates and lives are predicted for different specimens, strap materials and applied stress levels and are compared with the experimental tests. Good or acceptable agreement has been achieved for each case

Status of the SuperB project

An international collaboration has been settled to study a highluminosity e+e− collider operating at the Υ(4S) that would deliver a luminosity of the order of 1036 cm−2 s−1. This collider, called SuperB Factory, would use a combination of linear and storage ring tecniques. Such a collider would produce an integrated luminosity of about 10 ab−1 in a running year at the Υ(4S) resonance. Further possibilities include having longitudinally polarized electrons at the interaction point and operating at the J/ψ beam energy

Dynamic stiffness formulation for composite Mindlin plates for exact modal analysis of structures. Part II: Results and applications

The dynamic stiffness method for composite plate elements based on the first order shear deformation theory is implemented in a program called DySAP to compute exact natural frequencies and mode shapes of composite structures. After extensive validation of results using published literature, DySAP is subsequently used to carry out exact free vibration analysis of composite stringer panels. For each example, a finite element solution using NASTRAN is provided and commented on. It is concluded that the dynamic stiffness method is more accurate and computational efficient in free vibration analysis than the traditionally used finite element method

Dynamic stiffness formulation for composite Mindlin plates for exact modal analysis of structures. Part I: Theory

The dynamic stiffness formulation for both inplane and bending free vibration based on the first order shear deformation theory for composite plates is presented. The explicit terms of the dynamic stiffness matrices are also given. Plates with different boundary conditions are considered. Rotation and offset matrices for the element are developed and an assembly technique given. The Wittrick and Williams algorithm is modified to avoid the troublesome computation of the clamped–clamped natural frequencies when solving the free vibration problem. The validation of the theory and its application to real structures are illustrated in the second part of this paper

Optimisation of micro-structured waveguides in lithium niobate (z-cut)

We present an optimization procedure to improve the propagation properties of the depressed cladding, buried micro-structured waveguides formed in a z-cut lithium niobate (LN) crystal by high repetition rate femtosecond (fs) laser writing. It is shown that the propagation wavelength for which the confinement losses of ordinary (O) and extraordinary ordinary (E) polarizations are below 1 dB/cm can be optimized beyond 3 micro meter for hexagonal WG structures with seven rings of tracks

Analysis of navigation pattern in the sport of rowing

The effect of weather and environmental conditions on sports has been extensively studied over the last few years (Pezzoli et al., 2010). Based upon the studies of Lobozewicz (1981) and of Kay and Vamplew (2002), Pezzoli and Cristofori (2008) have studied the impact of some specific environmental parameters over different sports using a particular impact index divided into five classes. This analysis clearly shows that most of the outdoor sport activities are strongly influenced by the variation of meteorological parameters. However the impact of meteorological conditions on outdoor sport activities has not yet been extensively studied. The aim of this research is to show that an accurate assessment of wind and wave parameters enables decisive improvements in both training and race strategy planning. Furthermore this analysis provide a very innovative working method for the applied sport research. The work has been based on in-situ measurements of both environmental and performance parameters (wind direction, wind velocity, boat speed and stroke rate) made over different classes and in different race conditions during the 2009 FISA World Championship (Poznan, Poland). In particular a detailed environmental analysis was performed by measuring the wind direction, the wind speed and by evaluating the significant wave height and the wave peak period for each class during the semi-final phase and the final phase. It should be noted that, since wind is a key parameter affecting not only the boat speed but also the race strategy, the assessment of the wind velocity and of the wind direction has been made in connection with the boat movement. The comparison between coupled wind-wave data, boat speed and stroke rate evidently demonstrates that only crews that managed the adaption to changing in the environmental conditions from semi-final to final phase of the race, were able to get better results. References Kay, J., & Vamplew, W. (2002) Weather beaten: sport in the British climate. London: Ed. Mainstream Publishing. Lobozewicz, T. (1981) Meteorology in sport. Frankfurt: Ed. Sportverlag. Pezzoli, A,, Moncalero, M., Boscolo, A., Cristofori, E., Giacometto, F., Gastaldi, S., & Vercelli, G. (2010) The meteo-hydrological analysis and the sport performance: which are the connections? The case of the XXI Winter Olympic Games, Vancouver 2010, Journal of Sports Medicine and Physical Fitness, 50: 19-20. Pezzoli, A., & Cristofori, E. (2008) Analisi, previsioni e misure meteorologiche applicate agli sport equestri, in: 10th Congress "New findings in equine practices, Druento: Centro Internazionale del Cavallo Ed., p.38-4

Muon production and accumulation from positrons on target

In this paper we investigate the production of a muon beam by positrons on target. We describe the characteristics of the muon beam as produced by different target configurations. We present an optics for the muon accumulator ring, discussing how it fulfils the large energy acceptance requirement and the high order chromaticity correction at the target, as well as other parameters relevant to enhance the muon bunch quality. We discuss the muon beam dynamics through the ring for the configuration of the single-pass LEMMA scheme, and the optimization study performed with the goals of maximizing the muon bunch population and minimizing its emittance