scholarly journals Implementation of Life Estimation Algorithm of Composite High Speed Craft Shell due to Cyclic Sea Pressure

2020 ◽  
Vol 16 (32) ◽  
pp. 107-117
Author(s):  
Mohammad Naderian ◽  
Abdulreza Kabiri Ataabadi ◽  
◽  
Author(s):  
Xintian Liu ◽  
Yang Qu ◽  
Xiaobing Yang ◽  
Yongfeng Shen

Background:: In the process of high-speed driving, the wheel hub is constantly subjected to the impact load from the ground. Therefore, it is important to estimate the fatigue life of the hub in the design and production process. Objective:: This paper introduces a method to study the fatigue life of car hub based on the road load collected from test site. Methods:: Based on interval analysis, the distribution characteristics of load spectrum are analyzed. The fatigue life estimation of one - dimensional and two - dimensional load spectra is compared by compiling load spectra. Results:: According to the S-N curve cluster and the one-dimensional program load spectrum, the estimated range fatigue life of the hub is 397,100 km to 529,700 km. For unsymmetrical cyclic loading, each level means and amplitude of load were obtained through the Goodman fatigue empirical formula, and then according to S-N curve clusters in the upper and lower curves and two-dimensional program load spectrum, estimates the fatigue life of wheel hub of the interval is 329900 km to 435200 km, than one-dimensional load spectrum fatigue life was reduced by 16.9% - 17.8%. Conclusion:: This paper lays a foundation for the prediction of fatigue life and the bench test of fatigue durability of auto parts subjected to complex and variable random loads. At the same time, the research method can also be used to estimate the fatigue life of other bearing parts or high-speed moving parts and assemblies.


2013 ◽  
Vol 760-762 ◽  
pp. 1869-1873
Author(s):  
Li Min Xia ◽  
Xian Zhou ◽  
Dong Yan ◽  
Na Na Zhang ◽  
Xiao Yun Wu

This paper proposes a nearby phase search (NPS) algorithm based on BPS estimation algorithm in optical coherent receivers. And its suitable for arbitrary multi-level modulation. Making use of the continuity of phase change, the proposed NPS algorithm is applied to process nearby symbols by taking the pre-estimation phase of each symbol block as reference point. Compared to the traditional blind phase search (BPS) algorithm and its improved two-stage BPS algorithm, the performance of the proposed NPS algorithm is greatly improved in ultra-high speed coherent optical transmission system. By the simulation, the effectiveness and feasibility of the proposed algorithm are demonstrated in 28GBaud 16-QAM and 64-QAM system. Its shown that the computational complexity of the NPS algorithm greatly reduces in the guarantee of laser line width tolerance and bit error rate.


2018 ◽  
Vol 15 (3) ◽  
pp. 172988141877394 ◽  
Author(s):  
Ye Han ◽  
Zhigang Liu ◽  
DJ Lee ◽  
Wenqiang Liu ◽  
Junwen Chen ◽  
...  

Maintenance of catenary system is a crucial task for the safe operation of high-speed railway systems. Catenary system malfunction could interrupt railway service and threaten public safety. This article presents a computer vision algorithm that is developed to automatically detect the defective rod-insulators in a catenary system to ensure reliable power transmission. Two key challenges in building such a robust inspection system are addressed in this work, the detection of the insulators in the catenary image and the detection of possible defects. A two-step insulator detection method is implemented to detect insulators with different inclination angles in the image. The sub-images containing cantilevers and rods are first extracted from the catenary image. Then, the insulators are detected in the sub-image using deformable part models. A local intensity period estimation algorithm is designed specifically for insulator defect detection. Experimental results show that the proposed method is able to automatically and reliably detect insulator defects including the breakage of the ceramic discs and the foreign objects clamped between two ceramic discs. The performance of this visual inspection method meets the strict requirements for catenary system maintenance.


Author(s):  
Enrico Meli ◽  
Pierluca D’Adamio ◽  
Alice Innocenti ◽  
Lorenzo Marini ◽  
Luca Pugi ◽  
...  

In the present work the authors propose an innovative estimation algorithm for Weigh-in-motion (WIM) applications with the aim of estimating the axle or wheel loads of a generic train composition, starting from indirect track measurements. The WIM algorithm elaborates the set of experimental physical quantities chosen as track inputs, making use of estimation procedures based on least square minimization techniques. To perform an accurate estimation, the algorithm uses a flexible multibody model of the track and the vehicle. The novelty of the proposed solution is the general approach that allows to manage different kinds of measurement station and signal inputs (both experimental data and simulated ones) and the good robustness against numerical noise. The algorithm has been tested under any operating conditions through a wide simulation campaign, obtaining good results. Future developments will be based on the experimental data provided by Ansaldo STS and ECM SpA that supported the research activity.


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