scholarly journals Joint- or Crack-Opening Resistance Evaluation of Waterproofing Material and System for Structural Sustainability in Railroad Bridge Deck

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4229
Author(s):  
Kyu-Hwan Oh ◽  
Soo-Yeon Kim ◽  
Yong-Gul Park

A joint- or crack-opening resistance evaluation method for the selection of optimal waterproofing material for a railroad bridge deck is proposed. The joint opening range (mm) for the evaluation, and a typical load case of a high-speed double-track railroad bridge structure deck, is analyzed through the finite element method (FEM) and the results of analysis are used to calculate the minimum opening range. The evaluation method is then demonstrated with 4 commonly used waterproofing types of cementitious membrane system: a polyurethane coating system, self-adhesive asphalt sheet system and synthetic polymerized rubber gel composite asphalt sheet system. Five specimens of each type are subjected to continuous joint opening under 4 different joint width range conditions (1.5, 3.0, 4.5, and 6.0 mm), and the joint-opening resistance performance is compared. The proposal for the evaluation criteria and the specimen test results demonstrate how the evaluation method is pertinent for future selection of waterproofing membranes for the sustainability of high-speed railroad bridge deck structures.

2020 ◽  
pp. 039139882094493
Author(s):  
Shu Li ◽  
Juan Yan ◽  
Tingting Wu ◽  
Po-Lin Hsu

Objective: For ventricular assist devices utilizing levitation bearing technology, collision and wear of the rotor would occur if the bearing cannot resist disturbances from patient activities and vibration/shock impacts. The reliability of ventricular assist devices can be seriously affected, potentially impairing blood compatibility (e.g. thrombus generation) and threatening patient safety. In this article, we proposed a vibrational disturbance test protocol for ventricular assist devices. Methods: Two kinds of vibrational disturbances—translational and rotational—were defined and the disturbance levels determined as 6G and 10 rad/s per possible patient activity impact. A test platform was built according to the disturbance level requirements. Results: The test platform successfully generated the required disturbance. The vibration test evaluation criteria for ventricular assist device assistance (characterized by the pressure head, flow rate, and driving current waveform) were well verified. Conclusion: Compared with translational vibration, rotational vibration had a greater impact on the rotor. Accurate control of high-speed rotor is difficult because of the gyroscopic effect. As conventional random vibration tests cannot cover all risk situations, it is recommended that translational and rotational disturbance tests are carried out for levitation ventricular assist devices. We recommend that researchers and manufacturers pay attention to the vibrational impact of rotor-levitated ventricular assist devices.


2019 ◽  
pp. 40-44
Author(s):  
N.S. SOKOLOV ◽  
◽  
S.S. VIKTOROVA ◽  
I.P. FEDOSEEVA ◽  
G.M. SMIRNOVA ◽  
...  

Author(s):  
Hao Xu ◽  
Liuxin Chen ◽  
Qiongfang Li ◽  
Jianchao Yang

Due to the continuous changes of political environment, consumption habits, technological progress and other factors, the external environment of enterprises is full of uncertainty. The turbulence of external environment is not conducive to the long-term operation and development of enterprises, but also brings great challenges to the selection of suppliers. This makes the competition of enterprises focus on how to choose long-term cooperation suppliers in the uncertain external environment. In addition, due to the deterioration of the global environment, governments pay more and more attention to environmental pollution, and consumers are more and more inclined to green consumption, which makes many companies pay more and more attention to environmental indicators when selecting suppliers. In the case of external environment turbulence and serious environmental pollution, the evaluation and selection of green suppliers in uncertain environment is particularly important for the long-term development of enterprises. What’s more, when the supplier’s capability gap is small, the decision-maker often hesitates among several suppliers. In this paper, the hesitant fuzzy is used to describe the hesitant psychology of decision-makers in selecting suppliers, the variance fluctuation is used to describe the characteristics of hesitant fuzzy numbers, and the probability is used to measure the uncertainty of the environment. A green supplier evaluation model under the uncertainty environment is proposed, which comprehensively evaluates the green suppliers under the uncertain environment. Furthermore, it is compared with other methods that do not consider the uncertainty and the adaptability of evaluation method and right confirmation method, so as to reflect the influence of uncertainty to green supplier evaluation and the importance of adaptability of evaluation method and right confirmation method.


2014 ◽  
Vol 1048 ◽  
pp. 173-177 ◽  
Author(s):  
Ying Mei Wang ◽  
Yan Mei Li ◽  
Wan Yue Hu

Fabric shape style is one of the most important conditions in textile appearance evaluation, and also the main factor influences customer purchasing psychology. At first, the previous fabric shape style evaluation methods are classified and summarized, measurement and evaluation method discussed from tactic and dynamic aspects. Then, companied with computer vision principle, a non-contact method for measuring fabric shape style was put forward. In this method, two high-speed CCD cameras were used to capture fabric movement dynamically, fabric sequences image were obtained in this process. Used the image processing technology include pretreatment and feature point matching to get 3D motion parameters, it can provide data supports for shape style evaluation.


2021 ◽  
Vol 13 (5) ◽  
pp. 2615
Author(s):  
Junqing Wang ◽  
Wenhui Zhao ◽  
Lu Qiu ◽  
Puyu Yuan

Since application of integrated energy systems (IESs) has formed a markedly increasing trend recently, selecting an appropriate integrated energy system construction scheme becomes essential to the energy supplier. This paper aims to develop a multi-criteria decision-making model for the evaluation and selection of an IES construction scheme equipped with smart energy management and control platform. Firstly, a comprehensive evaluation criteria system including economy, energy, environment, technology and service is established. The evaluation criteria system is divided into quantitative criteria denoted by interval numbers and qualitative criteria. Secondly, single-valued neutrosophic numbers are adopted to denote the qualitative criteria in the evaluation criteria system. Thirdly, in order to accommodate mixed data types consisting of both interval numbers and single-valued neutrosophic numbers, the TOPSIS (Technique for Order Preference by Similarity to an Ideal Solution) method is extended into a three-stage technique by introducing a fusion coefficient μ. Then, a real case in China is evaluated through applying the proposed method. Furthermore, a comprehensive discussion is made to analyze the evaluation result and verify the reliability and stability of the method. In short, this study provides a useful tool for the energy supplier to evaluate and select a preferred IES construction scheme.


Author(s):  
J. F. Thring

With the identification of profitable freight areas and the selection of growth traffics for development has come the need to review in detail the running gear and, in particular, the suspensions of both 4-wheeled and bogie vehicles. This design review has been aimed at ensuring a high-speed capability for all new freight vehicles coupled with safety at all times, low maintenance costs, and maximum availability. After reviewing traditional suspensions, in wide use, with reference to their known strengths and weaknesses, the paper discusses in some detail the philosophy now being applied in B.R. design offices to new freight running gear, for both 4-wheeled and bogie vehicles, to ensure satisfactory achievement of technical objectives. Examples of new developments are provided, together with comments on progress to date.


2010 ◽  
Vol 163-167 ◽  
pp. 122-126 ◽  
Author(s):  
Ru Deng Luo ◽  
Mei Xin Ye ◽  
Ye Zhi Zhang

Orthotropic monolithic steel bridge deck system stiffened by U rib is very fit for high-speed railway steel bridges because of its excellent mechanical behaviors. Thickness of flange is a very important parameter of U rib and has influence on mechanical behaviors of orthotropic monolithic steel bridge deck system. Based on the engineering practice of Anqing Yangtze River Railway Grand Bridge, the kind and the extents of influences of thickness of flange of U rib on mechanical behaviors of orthotropic monolithic steel bridge deck system are studied with finite element analysis. The results show that thickness of flange of U rib has relative large positive influences on rigidity, strength and stability of orthotropic monolithic steel bridge deck system. 14~18mm is the appropriate range of thickness of flange of U rib for high-speed railway steel bridges.


2015 ◽  
Vol 723 ◽  
pp. 341-344
Author(s):  
Li Juan Zhang ◽  
Jiang Han ◽  
Zhang Ming Li

Research was conducted on the optimal selection of foundation improvement methods in the paper. Based on fuzzy optimization theory, four evaluation criteria such as construction time are used to evaluate the five improvement methods. The relative optimal degree 0.798 of dynamic-static consolidation method is the maximum which shows that the dynamic-static method is the optimal one; relative optimal degree and multi-evaluating criteria are used to evaluate multi-goals in the fuzzy optimization theory which will lead to the high optimal reliability result.


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