A new dust suppression hopper with a spiral guide plate embedded in the conventional hopper is proposed for the dust suppression of hopper transfer processes in this article. The Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) coupling numerical method is used to investigate the particle motion and flow field distribution of the hopper transfer process. The experiment is undertaken to determine dust suppression performance. The results show that the maximum particle velocity for the spiral hopper is dropped by 1.6 m/s compared to the conventional hopper, which means the collision of the particles and the spiral hopper is weakened. The axial airflow velocity of the spiral is reduced. In addition, the maximum dust concentration of the spiral hopper inlet is reduced by 56.9% due to the impact velocity of particles is small, and the secondary fugitive dust is controlled inside a semi-closed space formed by the spiral guide plate. It is thus concluded that the spiral hopper provides an effective way in dust control.

Compared with dual‐mass flywheel (DMF) and DMF with simple‐type centrifugal pendulum vibration absorber (CPVA), DMF with bifilar‐type CPVA has a better damping performance in the whole speed range of engine. The related research mainly focused on local models, such as dynamic model of DMF and dynamic model of CPVA, and the effect of the curvature path of CPVA on the damping performance. The reported models and methods are not sufficient for the system of DMF coupled with bifilar CPVA. Aiming at the deficiency of local models and the limitation of bench test, an integral model for DMF with bifilar CPVA is proposed and the real vehicle test is carried out in this study. Involving the moment of inertia of the centrifugal pendulum, the model considers the nonlinearities of DMF and bifilar CPVA. Afterward, the dynamic model of the automobile power transmission system equipped with the DMF with bifilar‐type CPVA is built, and the dynamic responses of the system are investigated under idling and driving conditions. According to the simulation results, DMF with bifilar‐type CPVA shows better vibration reduction performance in full‐speed range. Moreover, the key structural parameters R and l influencing the damping performance of DMF with bifilar CPVA are discussed. The results show that the sum of R and l is directly proportional to the damping effect. Finally, real vehicle tests under idling and driving conditions (engine speed from 750 r/min to 3400 r/min) are carried out. The test results show that the 2^nd order engine speed fluctuations are attenuated by more than 80% by DMF with bifilar CPVA with engine speed lower than 2000 r/min and are attenuated by more than 90% with engine speed higher than 2000 r/min. The experimental results are basically consistent with the simulation results, which verify the validity of the model.

On-fiber optical sensors, designed with chromogenic materials used as the fiber modified cladding, were developed for sensing environmental conditions. The design was based on the previously developed on-fiber devices. It is known that the light propagation characteristics in optical fibers are strongly influenced by the refractive index of the cladding materials. Thus, the idea of the on- fiber devices is based on replacing the passive optical fiber cladding with active or sensitive materials. For example, temperature sensors can be developed by replacing the fiber clad material with thermochromic materials. In this paper, segmented polyurethane-diacetylene copolymer (SPU), was selected as the thermochromic material for temperature sensors applications. This material has unique chromogenic properties as well as the required mechanical behaviors. During UV exposure and heat treatment, the color of the SPU copolymer varies with its refractive index. The boundary condition between core and cladding changes due to the change of the refractive index of the modified cladding material. The method used for the sensor development presented involves three steps: (a) removing the fiber jacket and cladding from a small region, (b) coating the chromogenic materials onto the modified region, and (c) integrating the optical fiber sensor components. The experimental set-up was established to detect the changes of the output signal based on the temperature variations. For the sensor evaluation, real-time measurements were performed under different heating-cooling cycles. Abrupt irreversible changes of the sensor output power were detected during the first heating-cooling cycle. At the same time, color changes of the SPU copolymer were observed in the modified region of the optical fiber. For the next heating-cooling cycles, however, the observed changes were almost completely reversible. This result demonstrates that a low-temperature sensor can be built by utilizing the chromogenic SPU copolymer as the modified cladding material.

In this paper, a new arc-surfaced frictional damper (AFD) is proposed and its hysteretic behavior is experimentally studied. Then the device is applied to container crane based on a seesaw mechanism. The major advantage of the seesaw damping system is that the long tension cables can be utilized as bracing between the seesaw member and the portal legs to avoid compression and buckling of the cables. A simplified trilinear force-displacement model on the basis of experimental results is adopted to represent the hysteretic behavior of AFD. After that, seismic responses of container crane with and without dampers to four earthquakes are studied using nonlinear dynamic time-history analysis. Besides this system, a diagonal-brace-AFD system is studied for comparison. A method based on the displacement and energy dissipation ratio is proposed to find the optimum slip force for seesaw damping system. Performance of AFD control system is assessed though various parameters including displacement and maximum portal frame drift angle. Results prove a feasible application of AFD control system to absorb large amounts of seismic energy and significantly reduce the structural responses.

Stacking of bulk solids in terminals, ships, trains, and other bulk solids storage yards is always challenging, considering the requirements of optimal utilization of storage areas. In this study, stacking shapes of a variety of bulk solids with different particle sizes were tested, and the curved shapes of the stockpiles were extracted to establish the actual three-dimensional models of the bulk solids accordingly. The three-dimensional curved stockpiles were used to design the bulk solids stacking strategy where the bulk stacking locations, the stacking volume, and the stacking flatness were optimized. A modified golden section method with a self-influenced factor was developed to improve the calculation efficiency of the stacking algorithm for bulk solids stacking flatness. Furthermore, the bulk solids stacking strategy and algorithm were verified by experiments. The results showed that the curved three-dimensional models were very close to the actual shapes of the bulk solids stockpiles, while the improved golden section method was more accurate and efficient than the traditional golden section method in determining the optimal values of the stacking volumes in terms of flatness. For the different bulk solids tested, the experiment results showed that good flat stacking can be achieved by using the developed stacking strategy.

Movement of the grab excavation process and stress state is the key to conduct large grab design. In this paper, discrete element theory is used to the simulation study of the large marine dredging digging grab process. Through the simulation of large-scale grab EDEM without deep reclaiming process, we get all the key parts of the grab variation of the force. Provide reference to reasonably determine speed of, hopper shape, arc discharge baffle structure, in order to design Grab mechanism design and improve the efficiency and reduce energy consumption.