This paper first studies the transition matrix formulation for the analysis of responses of an elastic halfspace with a buried tunnel subjected to obliquely incident waves. The basis functions are constructed using the moving P-, SV-, and SH-wave source potentials and to represent the scattered and refracted wave fields in series forms. The associated T-matrix expression of elastic inclusion is derived using Betti's third identity. Second, this study proposes a technique for calculating the integral representation of basis functions in the wave-number domain using the method of steepest descent. Finally, typical numerical results obtained under incident plane waves are presented for verification.

The FEM is used to study the effects of notch opening angle (β) and notch radius on the new strain-concentration factor (SNCF) for circumferentially V-notched cylindrical bars under static tension. The new SNCF has been defined under the triaxial stress state at the net section. Nevertheless, the conventional SNCF has been defined under uniaxial stress state. The new SNCF () is constant in the elastic deformation. The range where this elastic value remains constant increases with increasing β and increasing notch radius (ρo). The effect of the notch opening angle on the elastic decreases with increasing ρo. Particularly, the elastic of β = 120° is the minimum for all notch radii employed. The new SNCF increases from its elastic value to a peak value and then decreases with plastic deformation for notches with β = 120°. This peak value is the maximum . Nevertheless, for the notches with β < 120° becomes nearly constant or slightly decreasing after the first peak for ρo = 0.5 and 1mm. After that it increases to the maximum SNCF and then slightly decreases for further plastic deformation. The variations in with the ratio of tensile load to that at yielding at the notch root (P/PY) are nearly independent of stress-strain curve up to general yielding.

The coefficient C1 in the displacement coefficient method of FEMA-273/356 is the modification factor to relate the expected maximum displacements of elasto-plastic inelastic SDOF systems to displacements calculated for linear response. It permits the estimation of maximum inelastic displacements from maximum elastic displacements for structures with known lateral strength (usually, the existing structures). Recently, an improved C1 has been presented in FEMA-440 because it was shown that the C1 in FEMA-273/356 underestimates the maximum inelastic displacement demands of structures significantly. However, the improved C1 in FEMA-440 was derived from the earthquake ground motions recorded in California. In addition, it was mentioned in FEMA-440 that “caution should be used when extrapolating the results presented in the report for ground motions and site conditions that differ”. Because the characteristics of earthquakes occurred in Taiwan are different from those occurred in California, the coefficient for used in Taiwan needs to be modified. The objective of this paper is to propose appropriate C1 for use in Taiwan.

Fluid flow and heat transfer in duct fan flows with a 90° rectangular-wing turbulator, mounted on the top duct wall, were experimentally studied and compared with the bottom-wall turbulator results. Threecomponent velocities were measured to characterize the flow structures and to obtain near-wall flow parameters. Temperatures on heat transfer surfaces were measured to obtain Nusselt number distributions. Results show that the turbulator has the effect to increase the near-wall axial mean velocity, axial vorticity and turbulent kinetic energy, and, consequently, augment the heat transfer. The axial mean velocity and axial vorticity play an influential role on the heat transfer distributions for the flows across the top-wall and bottom-wall turbulators, respectively.

There has been a growing interest in developing the miniaturized fluidic devices for transportation, separation and detection of bio-samples. In many of these phenomena electrokinetic effects play an important role. Studies show that in fabricating these devices, if long channels are used, separation efficiency can be improved. In these devices, turns must be induced to integrate a long channel within the small area of a single chip. But these turns can cause a serious dispersion that can result in degraded separation quality. The present study shows that the dispersion in the channel can be reduced by using an optimized distribution for ζ-potential near the turns. A computer code based on the genetic algorithm has been developed to study the dispersion in L-shape and U-shape turns.

In this study, an analysis has been performed for heat and mass transfer of a steady laminar boundarylayer flow of an electrically conducting fluid with radiation effect of second grade subject to suction and to a transverse uniform magnetic field past a stretching sheet. Parameters Gr, Gc, Nr, M, Sc represent the dominance of the buoyant effect, radiative effect, magnetic effect and mass transfer effect which have presented in governing equations, respectively. The similar transformation and the finite-difference method have been used to analyze the present problem.

This paper focused on the pushover analysis of a frame structure infilled with low-rise reinforced concrete (RC) wall. The softening model of concrete as well as the elastoplastic model of reinforcement was considered in the analysis associated with the equilibrium and compatibility conditions. Accordingly, the shear load-deformation relationship of the wall subjected to monotonic lateral load can be analyzed through the proposed analysis procedure. Based on the relationship obtained, we employed a single equivalent structural strut represented by a nonlinear axial member, acting in the diagonal direction of the frame, in simulating the infilled RC wall to simplify the framed wall model. As a result, the sequential pushover analysis of the whole structure could be performed easily and efficiently based on the realistic procedure proposed.

To validate the proposed approach, reported results from the cyclic loading tests of fifteen specimens were adopted for the correlation. Based on the correlation, it is found that this study can provide an acceptable result of the pushover analysis and give an insight into progressive failure consequence of the framed wall structure. The proposed procedure simplifying the structural model helps the practical engineers get a higher efficiency while performing seismic evaluation and retrofit design of the high-redundancy frame structure with numerous infilled low-rise RC walls.

Students in dancing department routinely perform hours of dancing every day. Extreme ankle posture can subject the ankle of the dancers to high stress and can significantly increase the mobility of the ankle. This causes ankle sprain which occurs frequently during daily walking. Measurements of the ground reaction force (GRF) and the center of pressure (CoP) provide useful variables to analyze the walking patterns of dancers, which might help understand the causes of ankle sprain. The aims of this work were (1) to investigate the differences in gait patterns between dancers and non-dancers and (2) to explore the gait characteristics in dancers. Thirteen students in dancing department and twenty age-matched normal healthy subjects were recruited. All subjects were requested to walk along a 10-meter walkway. Results showed that the dancers have greater medial shear force of the GRF, and decreased the CoP velocity during the pre-swing phase, delayed peak-CoP velocity occurrence during the mid-stance, and straighter CoP trajectory through the forefoot at push off. The intense and demanding dancing activities change the walking pattern of dancers, which may lead to higher chance of getting ankle sprain.