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1 – 10 of 10Xiaogen Liu, Shuang Qi, Detian Wan and Dezhi Zheng
This paper aims to analyze the bearing characteristics of the high speed train window glass under aerodynamic load effects.
Abstract
Purpose
This paper aims to analyze the bearing characteristics of the high speed train window glass under aerodynamic load effects.
Design/methodology/approach
In order to obtain the dynamic strain response of passenger compartment window glass during high-speed train crossing the tunnel, taking the passenger compartment window glass of the CRH3 high speed train on Wuhan–Guangzhou High Speed Railway as the research object, this study tests the strain dynamic response and maximum principal stress of the high speed train passing through the tunnel entrance and exit, the tunnel and tunnel groups as well as trains meeting in the tunnel at an average speed of 300 km·h-1.
Findings
The results show that while crossing the tunnel, the passenger compartment window glass of high speed train is subjected to the alternating action of positive and negative air pressures, which shows the typical mechanic characteristics of the alternating fatigue stress of positive-negative transient strain. The maximum principal stress of passenger compartment window glass for high speed train caused by tunnel aerodynamic effects does not exceed 5 MPa, and the maximum value occurs at the corresponding time of crossing the tunnel groups. The high speed train window glass bears medium and low strain rates under the action of tunnel aerodynamic effects, while the maximum strain rate occurs at the meeting moment when the window glass meets the train head approaching from the opposite side in the tunnel. The shear modulus of laminated glass PVB film that makes up high speed train window glass is sensitive to the temperature and action time. The dynamically equivalent thickness and stiffness of the laminated glass and the dynamic bearing capacity of the window glass decrease with the increase of the action time under tunnel aerodynamic pressure. Thus, the influence of the loading action time and fatigue under tunnel aerodynamic effects on the glass strength should be considered in the design for the bearing performance of high speed train window glass.
Originality/value
The research results provide data support for the analysis of mechanical characteristics, damage mechanism, strength design and structural optimization of high speed train glass.
Details
Keywords
Sudarshan Maity and Tarak Nath Sahu
Bank mobilizes savings and transforms it into credit for investments in various sectors, which helps the economy running. The purpose of this paper is to examine the efficiency of…
Abstract
Purpose
Bank mobilizes savings and transforms it into credit for investments in various sectors, which helps the economy running. The purpose of this paper is to examine the efficiency of three bank groups in India with data spanning from 2009–2010 to 2018–2019.
Design/methodology/approach
The study uses data envelopment analysis for measuring the efficiency of the selected banks. It measures the efficiency both from the revenue dimension and from the supply-side dimension of financial inclusion.
Findings
The study finds that foreign banks on average are working efficiently far better than the public-sector and private-sector banks. It indicates that foreign banks in India are operating at 92.53% efficiency level, whereas private- and public-sector banks are operating at 90.20 and 86.04% efficiency levels, respectively. Further, the result of the Friedman test reveals that there is no significant difference in efficiency scores amongst these three bank groups. As major challenges, non-performing assets of the banking industry to be reduced by 15% as radial and 53.18% as slack.
Originality/value
One of the notable innovativeness of this study is that, unlike most of the previous studies that are mostly selected few banks and specific group, the present study may place itself as a unique inquiry in the domain of technical efficiency in macro concept by considering three major bank groups operating in India. An important contribution of the study is the classification of reasons behind the inefficiency, i.e. managerial or inappropriate scale size and further projections of input factors for the same level of output.
Details