排序方式: 共有19条查询结果,搜索用时 515 毫秒
11.
Fatigue design approach for the spot-welded T-type member using a simulated single spot-welded joint
In order to develop a fatigue design method for actual railroad car and commercial vehicle body structures using the fatigue
data of simulated single spot-welded lap joints, we first analyzed the stress distribution and evaluated fatigue strength
of spot-welded T-type members that are the components of actual railroad car and commercial vehicle body structures. Next,
fatigue design approach of these members using the fatigue data of single spot-welded lap joints was investigated. From our
results, we found that, even though there was a quantitative difference of fatigue strength between the single spot-welded
joint and the actual members over the same number of fatigue cycles, through the use of appropriate correction, the fatigue
design criterion of actual spot-welded members, such as those used in railroad car and commercial vehicle body, can be predicted
using the fatigue strength of single spot-welded joint. 相似文献
12.
In this paper, in order to save time and cost for the fatigue design and to develop the optimum approaches for accelerated
life prediction of the fillet gas welded joints, the (Δσ)R − Nf relationship was obtained from actual fatigue test data, including welding residual stress. Based on these results, the (Δσa)R − (Nf)ALP relationship derived from the method of statistical probability analysis was compared with the actual fatigue test data.
From the result, the optimum statistical distribution for the accelerated life prediction was analyzed to be the lognormal
distribution for the fillet-type, gas-welded joint. The mean accuracy of the accelerated life prediction was assessed to be
85∼95% of the actual test life at the 95% reliability level and ±15% standard deviation. Therefore, it is expected that the
accelerated life prediction will provide a useful method for determining the criterion for fatigue design and for predicting
a specific target life. 相似文献
13.
M. H. Lee H. M. Lee K. S. Lee S. K. Ha J. I. Bae J. H. Park H. G. Park H. J. Choi H. H. Chun 《International Journal of Automotive Technology》2011,12(5):733-744
In this paper, a hardware-in-the-loop simulation (HILS) system was developed before the development of an electric power steering
(EPS) system in a vehicle. This study was focused on the establishment of the HILS system. Driving conditions are simulated
with the HILS system. The actual steering input parameters are confirmed on the monitor while driving the HILS system. The
steering forces observed in the simulation with the developed HILS system are similar to those in real vehicle tests. The
developed HILS system can be applied in the development of various types of EPS systems. 相似文献
14.
H. S. Heo S. J. Bae H. K. Lee K. S. Park 《International Journal of Automotive Technology》2012,13(2):167-173
In a conventional MPI engine, a pulsation damper is usually mounted on the fuel rail to diminish undesirable noise in the
vehicle cabin room; however, pulsation dampers are quite expensive. Therefore, several studies have focused on reducing fuel
pressure pulsation by increasing the self-damping characteristics of the fuel rail. This paper details the development of
a fuel rail that reduces pulsation using a self-damping effect. Using an oil hammer simulation technique, pressure pulsation
characteristics were investigated with respect to the aspect ratio of the cross-section, wall thickness, and fuel rail material.
Increasing the aspect ratio and decreasing the wall thickness efficiently reduced the pressure pulsation. In addition, the
pressure pulsation characteristics were investigated with respect to the resonant engine speed and injection period. These
simulated data can be used to reduce the pressure pulsation peak and to avoid the resonant point in the design stage during
the development of a fuel rail. 相似文献
15.
Dong-Myung Bae 《船舶与海洋工程学报》2012,11(2):184-190
Fatigue cracks and fatigue damage have been important issues for ships and offshore structures for a long time.However,in the last decade,with the introduction of higher tensile steel in hull structures and increasingly large ship dimensions,the greater attention should be paid to fatigue problems.Most research focuses on how to more easily access the fatigue strength of ships.Also,the major classification societies have already released their fatigue assessment notes.However,due to the complexity of factors influencing fatigue performances,such as wave load and pressure from cargo,the combination of different stress components,stress on concentration of local structure details,means stress,and the corrosive environments,there are different specifications with varying classification societies,leading to the different results from different fatigue assessment methods.This paper established the Det Norske Veritas(DNV) classification notes "fatigue assessment of ship structures" that explains the process of fatigue assessment and simplified methods.Finally,a fatigue analysis was performed by use data of a real ship and the reliability of the result was assessed. 相似文献
16.
H. J. Kim C. H. Bae S. H. Kim H. Y. Lee K. J. Park M. W. Suh 《International Journal of Automotive Technology》2009,10(1):123-129
Urban transit is a complex system that contains both electrical and mechanical entities; therefore, it is necessary to construct
a maintenance system for ensuring safety during high-speed driving. Expert systems are computer programs that use numerical
or non-numerical domain-specific knowledge to solve problems. This research aims to develop an expert system that diagnoses
the causes of failures quickly and displays measures to correct them. For the development of this expert system, the standardization
of a failure code classification and the creation of a Bill of Materials (BOM) were first performed. Through the analysis
of both failure history and maintenance manuals, a knowledge base has been constructed. Also, for retrieving the procedure
of failure diagnosis and repair linking with the knowledge base, we have built a Rule-Based Reasoning (RRB) engine with a
pattern matching technique and a Case-Based Reasoning (CBR) engine with a similar search method. Finally, this system has
been developed as web based in order to maximize accessibility. 相似文献
17.
Chang-Kook Chae Byung-Kook Bae Kwang-Joon Kim Joon-Hong Park Nam-Chan Choe 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2000,33(5):327-349
This paper presents a feasibility study on using the rubber bushing itself as a sensor for the identification of transmission forces in vehicle suspension systems. The method starts from the idea that the transmission forces can be related to the deformation of the rubber bushing by an appropriate model and the deformation of the rubber bushing can be obtained by estimation of the relative vibration across the bushing. Simple theories are presented to deal with modeling of a given geometry of rubber bushing by a concentric spring and damper, correlating of measurements of the vibration on the links to the stiffness and damping parameters, and selection of the vibration measurement positions. Importance of the measurement position selection in relation to the measurement noise is illustrated by simulation studies. Then, validity of the proposed indirect approach will be shown by applications to a rear suspension system of dual link type. 相似文献
18.
Jingyu Choi Kyunggook Bae Junbeom Wi Sunghyun Ahn Hyunsoo Kim 《International Journal of Automotive Technology》2018,19(1):147-157
In this paper, a design method for a PHEV hydraulic control system was proposed considering motor thermal management. Dynamic models of the target PHEV were developed including the hydraulic system, which consists of one mechanical and one electric oil pump. The required motor cooling flow was designed based on the motor temperature, which was obtained from a one-dimensional thermal equivalent circuit model including the heat source and oil spray cooling. Combining the PHEV powertrain model, hydraulic control system model, and the motor thermal model including the cooling system, an integrated simulator was developed for the target PHEV. Using the integrated simulator, the temperatures of MG1 and MG2 were investigated for various motor cooling flow rates when the PHEV underwent a highway driving cycle. The energy consumption of the hydraulic control system was also evaluated. It was found from the simulation results that a hydraulic control system of the target PHEV could be designed that satisfied the required flow for the motor cooling, lubrication and brake control using the design procedure proposed in this study. 相似文献
19.
Hyung Rim Choi Jae Joong Kim Jae Kee Lee Kang Bae Lee Joong Jo Shin 《Maritime Policy and Management》2018,45(3):388-402
To ensure the successful implementation of China’s Belt and Road (B&R) Initiative, it is essential to enable the real-time monitoring of containers’ locations, prevent theft during cargo delivery, ensure more efficient logistics management and reduce carbon emissions. For this, it is vital to have an economic and effective system to track and control containers across multiple countries. However, this requirement cannot be met by today’s container tracking systems because they are either limited within the borders of each country or expensive to employ internationally. This study thus presents a framework for an IoT-based container tracking system that enables users not only to grasp the international flow of container movement with one check but also to achieve smooth cross-border procedures. To verify the system’s performance, an empirical test was made for an actual container shipped from Korea to Poland. The test results showed that the system could successfully track the location of the container in real time across international borders. Last, this study discusses the policy development and international cooperation that should take place to enable the introduction of this container tracking system. 相似文献