Mechanical Properties and Structural Optimization of Continuous Welded Rail on Super-Long-Span Suspension Bridges for High-Speed Railway

In order to ensure driving safety and comfort, it is necessary to figure out the complex interaction between continuous welded rail (CWR) and suspension bridges for high-speed railway. A spatial finite element model for a 1092 m main span suspension bridge was established based on the bridge-track interaction theory. A specific correction method was put forward to keep the rail in a zero-stress state when just laid. Three rail expansion joint (REJ) layout schemes were proposed according to practical engineering experience. Both static and dynamic analysis methods were used to evaluate the feasibility of these schemes. The results show that the REJ should be laid at the position with a distance away from the primary beam end, and the beam with more substantial integral stiffness should be preferentially selected. For the recommended scheme, the REJ expansion reaches more than 380 mm under expansion load. The factors affecting the REJ expansion from major to minor are temperature, earthquake, rail fracture, braking, and bending load. The superposition effect of the above factors is suggested to be considered in the selection of REJ range.

FREE VIBRATION OF SKEW LAMINATES – A BRIEF REVIEW AND SOME BENCHMARK RESULTS

This study investigates and reviews prior research works on skew composite laminates. The equivalent single layer theories are explored and discussed. An exhaustive review on static and dynamic analysis of composite skew laminates is also presented. Subsequently, a nine node isoparametric plate bending element is used for free vibration analysis of laminated composite skew plate with central skew cut out. The effect of shear deformation is incorporated in the formulation considering first order shear deformation theory. Two types of mass lumping schemes are analysed to study the effect of rotary inertia. Certain numerical examples of plates having different skew angles, skew cut out sizes, boundary conditions, thickness ratios (h/a), aspect ratios (a/b), fiber orientations and number of layers are solved which will be useful for benchmarking of future studies.

Analysis of the structural behavior of a historical mosque damaged due to an earthquake: Sofular mosque example

Since the earliest period of history, many civilizations have ruled our country. Historical structures, which we inherited from these civilizations, should be transferred safely to future generations. For this purpose, it is essential to clearly determine the behavior of these historical structures. In the present study, one of these historical structures, Sofular mosque located in Merzifon, was examined in detail by static and dynamic analysis. In the analysis, the mechanical properties of the material obtained by experimental studies were used. In the static analysis, the mosque was analyzed under its own weight, and it was obtained that the stresses have large values at the supports of the main dome. So, it can be said that the dome has to be supported at these points. The results of the modal analysis show that the mosque has translational displacements with great mass ratios through two orthogonal directions. This shows that the mosque will have out of plane deformation during an earthquake. Also, under the dynamic effects of seismic forces, it was identified that critical out of plane deformations could occur at the upper parts of the eastern and western facades. Also, it is clear that large stress and deformation values could occur at the narthex part. Moreover, it is determined that the dome portion is involved in translational motion and can be damaged during an earthquake.

Ecological Approach for the Evaluation of Structure and Sustainability in the Tourism Industry

Badaling is the main tourism area in Beijing. The development of tourism has generated considerable economic benefit in this region, but the tourism industry also brought considerable environmental pressure. To obtain a targeted upgrade plan for metropolitan tourism industry, static and dynamic analysis methods were used to quantitatively estimate the structure of the tourism industry in this region. In addition, the ecological footprint and ecosystem capacity models were used to evaluate the sustainable development of tourism. The results show that: (1) The structure of tourism in Badaling is better than that of Beijing, but the growth rate of tourism earnings is slower than the average value in Beijing. Overall, the region lacks competitiveness and the tourism industry in the area is in dire need of an upgrade; (2) the total ecological footprint due to tourism in the Badaling region is 381,098.28 hm2, and the ecosystem capacity is 4509.61 hm2. It is in an obvious ecological deficit, and the development of the tourism industry is unsustainable. To relieve the pressure on the ecology in the Badaling region, we propose four policy suggestions: (1) develop disadvantaged sectors and enhance tourism industry competitiveness, (2) boost tourist transportation revenues relying on the Winter Olympic Games, (3) grow cultural and creative products and expand sales channels, and (4) strengthen inter-regional cooperation and alleviate local ecological pressure.

Static and Dynamic Analysis of Non-Pneumatic Tires Based on Experimental and Numerical Methods

Since the beginning of their production, pneumatic tires have experienced tremendous improvements in structure and materials, becoming the dominant design in the world tires market. Nevertheless, relying upon pressurized air, they are affected by maintenance and security issues that can lead to fatal accidents. Therefore, tire-makers are investigating new tire designs, called Airless or Non-Pneumatic, with the aim of removing air-related problems. The research about such tires is still at an early stage, especially if compared to the one conducted on the pneumatic ones. In this paper, the development of a methodology capable of studying the mechanical behavior of a Non-Pneumatic Tire (NPT) by means of experimental data and numerical approach is illustrated. The experimental activities consisted of a scanner acquisition of the NPT and a footprint analysis for the calculation of the radial stiffness and contact patch pressure distribution. Moreover, the Digital Image Correlation (DIC) technique was applied to carry out a more specific study about the spoke’s deformation. From the acquired 3D model, a calculation of the NPT vertical deflection with finite element analysis (FEA) was performed—validating the model and then submitting it to a steady state analysis—that allows the simulation of a steady state rolling tire with the possibility to replicate different values of slip ratio. The results of the experimental activities are in good agreement with the ones obtained with FEA, further validating the developed methodology.

Transfer of Cellular Content from the Allogeneic Cell-Based Cancer Vaccine DCP-001 to Host Dendritic Cells Hinges on Phosphatidylserine and Is Enhanced by CD47 Blockade

DCP-001 is a cell-based cancer vaccine generated by differentiation and maturation of cells from the human DCOne myeloid leukemic cell line. This results in a vaccine comprising a broad array of endogenous tumor antigens combined with a mature dendritic cell (mDC) costimulatory profile, functioning as a local inflammatory adjuvant when injected into an allogeneic recipient. Intradermal DCP-001 vaccination has been shown to be safe and feasible as a post-remission therapy in acute myeloid leukemia. In the current study, the mode of action of DCP-001 was further characterized by static and dynamic analysis of the interaction between labelled DCP-001 and host antigen-presenting cells (APCs). Direct cell–cell interactions and uptake of DCP-001 cellular content by APCs were shown to depend on DCP-001 cell surface expression of calreticulin and phosphatidylserine, while blockade of CD47 enhanced the process. Injection of DCP-001 in an ex vivo human skin model led to its uptake by activated skin-emigrating DCs. These data suggest that, following intradermal DCP-001 vaccination, local and recruited host APCs capture tumor-associated antigens from the vaccine, become activated and migrate to the draining lymph nodes to subsequently (re)activate tumor-reactive T-cells. The improved uptake of DCP-001 by blocking CD47 rationalizes the possible combination of DCP-001 vaccination with CD47 blocking therapies.

Full-Scale Field Experimental Investigation on the Intended Irregularity of CWR Track in Vertical Plane

The purpose of the following paper is to present the author’s experimental field investigations of a jointless railway track subjected to a generated imperfection and analysis of track response to applied static loads. An optical measurement system, Pontos, was used for the static and dynamic analysis of the track’s deflections in 3D. The investigations allow us to recommend a direct application of this system for the non-contact measurement, visualization and analysis of simulated defects in the jointless track, as presented by the author. It is stated that simulation of an effect called the hanging sleeper, a short irregularity in the railway track with the initial parameters provided (a gap and a length of irregularity), is possible. The proposed method, based on the measurement in the loaded track (a static load from the locomotive wheels), allows for a description of the effect of the changing track support condition. Moreover, it also proves its usefulness for the analysis of the changes in deflection and stress values and the force transferred from the rail on the railway sleeper and for the assumed shape of defects simulating the short irregularities arising in the operated railway track. The arising irregularity in the track affects driving comfort and the safety of travellers.

Investigation of an electrostatically actuated imperfect circular microplate under transverse pressure for pressure sensor applications

In this paper, we present static and dynamic analysis of an electrostatically actuated imperfect circular microplate under transverse pressure. In modelling of the microplate, we have included both von Kármán geometric and electrostatic force nonlinearities in the development of the equation of motion. The equation of motion has been solved using Galerkin based reduced order modelling technique. The developed reduced order model has been first validated by comparing it with finite element simulation results. Further, the effects of imperfection as initial curvature and uniform transverse pressure have been investigated on the static and dynamic characteristics of the electrostatically actuated circular microplate. We have also investigated the effects of imperfection and applied DC voltage on the pressure sensitivity of the circular microplate. We have found that both imperfection and electrostatic load are responsible for appreciable variations in sensitivity. This detailed investigation is useful to design an imperfect micro pressure sensor.