Research on the influence of the normal vibration on the friction-induced vibration of the water-lubricated stern bearing

During the slow voyage of ships, the friction-induced vibration noise often occurs in the contact region of the water-lubricated stern bearing and the tail shaft. The lateral vibration can impact the normal motion of the contact surface, then change the dynamic friction force, finally affect the behaviour of the friction-induced vibration. By adding the movement of the stern shaft journal into the normal load description of the dynamic friction, the equation of friction-induced vibration considering the effect of normal vibration was established. Then the effect law of normal vibration on friction-induced vibration was discussed by numerical simulation and test. The results show that the normal vibration would make the friction-induced vibration appear quasi-periodic, chaotic trend, and narrow the speed range in which the noise of friction-induced vibration appears

Seismic performance and most unfavorable and favorable Load distributions of steel storage rack: an optimization approach

In the current rack seismic design, the load distribution is generally considered to be placed uniformly on the rack, but the reality usually differ. In this paper, the objective is to identify the most unfavorable and favorable load distribution of the braced and unbraced racks under seismic loading through a stochastic optimization - Genetic Algorithm (GA). The GA optimization is performed with an established computational models of racks and the pushover analysis is integrated to evaluate seismic performance of the racks. It is analyzed that the distribution of load has a great influence on the seismic performance of steel racks. During the optimization, including the optimized solutions, there are other loading distributions that will make the racks fail with the seismic requirements. Statistical summary of these load pattern results create a cloud map. The cloud map from the optimization results show that the most unfavorable load distribution is in a ‘凸’ shape of the 3D space of the racks and the safe load distribution holds a ‘凹’ shape for braced racks. Meanwhile, unbracing racks have the characteristics of an unfavorable load distribution of a ‘卩’ shape. The gravity center of the loading has an apparent impact on the braced rack’s seismic performance such as the number of load carried by the columns in the back pulling zone, the total horizontal seismic force, and the distribution of local at the dangerous position. On the other hand, no obvious impact of the gravity.We are grateful to Natural Science Foundation of Jiangsu Province for their financial support(No: BK20191268) to this paper

Recent Progress of Remediating Heavy Metal Contaminated Soil Using Layered Double Hydroxides as Super-Stable Mineralizer

Heavy metal contamination in soil, which is harmful to both ecosystem and mankind, has attracted worldwide attention from the academic and industrial communities. However, the most-widely used remediation technologies such as electrochemistry, elution, and phytoremediation. suffer from either secondary pollution, long cycle time or high cost. In contrast, in situ mineralization technology shows great potential due to its universality, durability and economical efficiency. As such, the development of mineralizers with both high efficiency and low-cost is the core of in situmineralization. In 2021, the concept of ‘Super-Stable Mineralization’ was proposed for the first time by Kong et al.[1] The layered double hydroxides (denoted as LDHs), with the unique host–guest intercalated structure and multiple interactions between the host laminate and the guest anions, are considered as an ideal class of materials for super-stable mineralization. In this review, we systematically summarize the application of LDHs in the treatment of heavy metal contaminated soil from the view of: 1) the structure–activity relationship of LDHs in in situ mineralization, 2) the advantages of LDHs in mineralizing heavy metals, 3) the scale-up preparation of LDHs-based mineralizers and 4) the practical application of LDHs in treating contaminated soil. At last, we highlight the challenges and opportunities for the rational design of LDH-based mineralizer in the future

The Ninth Visual Object Tracking VOT2021 Challenge Results

acceptedVersionPeer reviewe

Back Bay Battery Simulation Reflective Essay

The success of an organization’s innovation strategy relies on a clearly defined innovation theme. In this article, the author will delve into the concept of disruptive innovation and explore how to achieve Horizon 2 ideas. Horizon 2 ideas involve extending the business’s current model and core competencies to reach new customers, markets, and even new business objectives in different segments. The business model extension under Horizon 2 focuses on the organization’s mid-term goals, typically taking 24 to 36 months to yield results. Drawing insights from the Harvard Business Review’s Back Bay Battery (BBB) simulation, this article presents the implementation of an innovation strategy within the BBB company. The aim is to assist the company in enhancing its business model and transitioning into the high-end market. The latter part of the article will shed light on the challenges associated with implementing this strategy in a real-world firm and the results it can deliver to the organization. Specifically, it will explore the effectiveness of the strategy in achieving disruptive innovation within the employee market, where the company intends to use the new business model to tap into new markets

Load Effect of Automated Truck Platooning on Highway Bridges and Loading Strategy

Automated truck platooning (ATP) has gained growing attention due to its advantage in reducing fuel consumption and carbon emissions. However, it poses serious challenges to highway bridges due to the load effect of multiple closely spaced heavy-duty trucks on the bridge. In China, ATP also has great application prospects in the massive and ever-increasing highway freight market. Therefore, the load effects of ATP on bridges need to be thoroughly investigated. In this study, typical Chinese highway bridges and trucks were adopted. ATP load models were designed according to the current Chinese road traffic regulations. The load effects of ATP on highway bridges were calculated using the influence line method and evaluated based on the Chinese bridge design specifications. Results show that the load effect of ATP on bridges increases with the increase in the gross vehicle mass and the truck platooning size but decreases with the increasing inter-truck spacing and the critical wheelbase. The Grade-I (best quality standard) highway bridges are generally capable of withstanding the ATP loads, while caution should be exercised for other bridges. Strategies for preventing serious adverse impacts of ATP load on highway bridges are proposed

Free-Form Shape Optimization of Advanced High-Strength Steel Members

The high yielding strength of advanced high-strength steel (AHSS) provides great opportunities for cold-formed steel (CFS) members with much higher load-carrying capability. However, if manufactured into the traditional cross-section shapes, such as C and Z, the material advantage cannot be fully exploited due to the cross-section instabilities. The purpose of this study was to establish a shape optimization method for cold-formed sections with AHSS and explore the potentially material efficiency that AHSS could provide to these sections in terms of their axial strength. In this study, the insights provided from the elastic buckling analysis and nonlinear finite element (FE) simulations of a set of traditional CFS sections were employed to determine the appropriate section size and length for optimization. Then, the optimization method was established using the particle swarm optimization (PSO) algorithm with the integration of computational analysis through CUFSM and the design approach (i.e., the direct strength method, DSM). The objective function is the maximum axial strength of the CFS sections manufactured with AHSS using the same amount of material (i.e., the same cross-section area). Finally, the optimal sections were simulated and verified by FE analysis, and the characteristics of the optimal cross-sections were analyzed. Overall, the optimization method in this paper achieved good optimization results with greatly improved axial strength capacity from the optimal sections

An automated penetration semantic knowledge mining algorithm based on bayesian inference

10.32604/cmc.2021.012220Computers, Materials and Continua6632573-258

Free-Form Shape Optimization of Advanced High-Strength Steel Members

The high yielding strength of advanced high-strength steel (AHSS) provides great opportunities for cold-formed steel (CFS) members with much higher load-carrying capability. However, if manufactured into the traditional cross-section shapes, such as C and Z, the material advantage cannot be fully exploited due to the cross-section instabilities. The purpose of this study was to establish a shape optimization method for cold-formed sections with AHSS and explore the potentially material efficiency that AHSS could provide to these sections in terms of their axial strength. In this study, the insights provided from the elastic buckling analysis and nonlinear finite element (FE) simulations of a set of traditional CFS sections were employed to determine the appropriate section size and length for optimization. Then, the optimization method was established using the particle swarm optimization (PSO) algorithm with the integration of computational analysis through CUFSM and the design approach (i.e., the direct strength method, DSM). The objective function is the maximum axial strength of the CFS sections manufactured with AHSS using the same amount of material (i.e., the same cross-section area). Finally, the optimal sections were simulated and verified by FE analysis, and the characteristics of the optimal cross-sections were analyzed. Overall, the optimization method in this paper achieved good optimization results with greatly improved axial strength capacity from the optimal sections

Load Distribution Optimization of Steel Storage Rack Based on Genetic Algorithm

The distribution of load has high uncertainty, which is the main cause of a rack structure’s instabilities. The objective of this study was to identify the most unfavorable and favorable load distributions on steel storage racks with and without bracings under seismic loading through a stochastic optimization—a genetic algorithm (GA). This paper begins with optimizing the most unfavorable and favorable load distributions on the steel storage racks with and without bracings using GA. Based on the optimization results, the failure position and seismic performance influencing factors, such as the load distributions on the racks and at hazardous positions, are then identified. In addition, it is demonstrated that the maximum stress ratio of the uprights under the most unfavorable load distribution is higher than that under the full-load normal design, and it is not the case that the higher the center of gravity the more dangerous the steel storage rack is, demonstrating that the load distribution pattern has a significant impact on the structural safety of steel storage racks. The statistics of the distributions of the load generated during the optimization of the GA and the contours of the probability distributions of the load are generated. Combining the probability distribution contours and the GA’s optimization findings, the “convex” distribution hazard model and the “concave” distribution safety model for a steel storage rack with bracings are identified. In addition, the features of the distribution hazard model and the load distribution safety model are also identified for steel storage racks without bracings