This study integrates a large eddy simulation model to investigate the effect of a submerged rectangular cylinder on the hydrodynamics of free surface flows. The simulation results are validated by the results of flume experiments. Then the numerical model is utilized to examine the influences of Reynolds number, Froude number, and blockage ratio on the flow field and the force coefficients of the deck. The simulation results reveal that the drag coefficient is dependent on the deck’s Froude number and blockage ratio of the bridge deck, rather than the Reynolds number. For both subcritical and transcritical flows, the drag coefficient increases as the blockage ratio increases. However, due to the wave-induced drag, the drag coefficient of the cylinder in transcritical flows is greater than that in subcritical flows with the same blockage ratio. On the other hand, the lift coefficient is a function of the submergence ratio and the deck’s Froude number. The separation shear flow on the upper side of...

An upgraded piezoelectric film type real-time scour monitoring sensor installed along the bridge pier is presented. The core idea of developing this scouring sensing system is based on the physical characteristic that output voltage can be generated as the piezoelectric film is deformed by the flowing media. Therefore, a sensing device can be constructed by mounting piezoelectric thin films along the rod at a fixed distance and inserting them into a guide rail beside the bridge pier. The piezoelectric film embedded in the soil of the riverbed is undisturbed and the output voltage is much smaller than the one disturbed by the water current. From the output signals of all the piezoelectric sensors with known locations along the depth of the pier foundation, one can trace the variation of the soil/water interface before, during and after a flood. Compared with other types of scouring sensors, this piezoelectric type scouring sensor is durable, sensitive, and cost effective and works in real-time without the need for power. In this paper, a signal processing technique and performance tests in laboratory of this novel piezoelectric film type scouring device are introduced first. The installation and performance of the system in the field is also addressed.

To install the continuous welded rail (CWR) on the viaduct, it is necessary to consider the accumulated axial force owing to temperature difference and the additional force of the rail exerted by the track-bridge expansion as a result of temperature difference, the so-called track–bridge interaction. This paper used A-thermal fiber bragg grating (FBG) sensors which do not need the temperature compensation, and electronic sensors as monitoring instruments to detect performance changes in CWR axial force. These optical fiber sensors coupled with the developed track axial force calculation software and monitoring platforms calculate the axial force distribution along the track to be monitored. To better understand the influence of the change in the bridge’s structure expansion and the change in concrete slab strain on track axial forces, sensors are set up at bridge expansion joints (EJs), rail ends, and concrete slab beds. Monitoring results show that optic fiber sensors provide sensitive, clear, and stable...

A computationally efficient method is proposed for analyzing train and bridge dynamic interaction responses based on the vector form intrinsic finite-element method. The proposed method does not need to establish a large number of complicated dynamic coupling equations for the train and bridge, in contrast to the traditional finite-element method. A train with multiple cars traveling over a railway bridge with multiple spans was analyzed, and two computational models were considered: two-axle and coach models. The effects of rail irregularity and rail ballast were also considered. In the proposed method, the bridge is modeled as mass particles linked by a series of massless beam elements, and the train is simulated by mass particles. The motions of the mass particles are governed by Newton’s second law, and the central difference scheme is employed to solve the equation of motion for each mass particle. The fictitious reverse-motion procedure is employed to obtain the pure deformations of the massless beam elements, from which the internal forces exerted on the mass particles are evaluated. Assembly of the global stiffness matrix is avoided, and each mass-particle motion is calculated independently, which makes the proposed method easy and efficient. Compared with existing analytical and numerical methods, the proposed method provides simpler modeling of the dynamic interaction between the train and bridge and more efficient computation. Furthermore, the proposed method can yield very accurate results.

CIP2A is an oncoprotein that upregulates p-Akt and promotes cancer cell proliferation and survival. The proteasome inhibitor bortezomib has been shown to reduce CIP2A and lead to cell apoptosis. Here; we modified the functional group of bortezomib to generate a series of novel compounds and conducted a structure–activity relationship (SAR) study. The results showed that compound 1 was able to repress CIP2A expression and cell apoptosis in the same manner as bortezomib, but with less potency in inhibition of proteasome activity. This finding provides a new direction for the design of CIP2A inhibitors.

This paper presents an in-depth study of the stress wave behavior propagating in a Rayleigh–Love rod with sudden cross-sectional area variations. The analytical solutions of stress waves are derived for the reflection and transmission propagation behavior at the interface of the cross-sectional area change in the rod, considering inertia and Poisson’s effects on the rod material. Examples solved using the finite element method are provided to verify the correctness of the analytical results. Based on the forward analysis of Rayleigh–Love wave propagation in a rod impacted by a striker rod, an impact-echo-type nondestructive testing (NDT) method is proposed to conduct defect assessment in rod-type structural components with sudden cross-sectional area changes within a cover medium. This proposed NDT method can identify the location, extension, and cross-sectional area drop ratios of an irregular zone in the rod to be inspected.