scholarly journals Transient Analysis and Safety Assessment of Turbofan Engine Structures during Bird Ingestion

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Gang Luo ◽  
Chi Ma ◽  
Wei Chen ◽  
Lulu Liu ◽  
Zhenhua Zhao
Keyword(s):  
Transient Analysis ◽  
Safety Assessment ◽  
Safety Analysis ◽  
Assessment Method ◽  
Dynamic Responses ◽  
Structural Safety ◽  
Turbofan Engine ◽  
Load Carrying ◽  
Large Bird ◽  
Bypass Ratio

The high bypass ratio turbofan engine’s load-carrying structure transient response during bird ingestion was analyzed in accordance with the engine bird ingestion certification regulations, the principles of structural safety assessment were represented, and the structural safety analysis and assessment method of Turbo-Fan engine during bird ingestion were proposed. A high bypass ratio turbofan engine’s FEM was established and verified the rationality when its’ operation. Large bird ingestion into an engine’s procedure was conducted, the dynamic responses of key components on engine’s load-carrying structures during the bird ingestion were discussed, and the safety assessment consequence was obtained. We draw a conclusion that the relevant analysis/simulation data could be submitted to engine certification administration as key documents, the structural safety analysis and assessment method of turbofan engine due to bird ingestion could be applied as analysis and prediction work in the engine bird ingestion certification.

An Online Quantified Safety Assessment Method for Train Service State Based on Safety Region Estimation and Hybrid Intelligence Technologies

2015 ◽  
Vol 25 (03) ◽  
pp. 493-511
Author(s):  
Yong Qin ◽  
Shan Yu ◽  
Yuan Zhang ◽  
Limin Jia ◽  
Xiaoqing Cheng
Keyword(s):  
Safety Assessment ◽  
Safety Analysis ◽  
Assessment Method ◽  
Rolling Bearings ◽  
Safety Risk ◽  
Hybrid Intelligence ◽  
Local Mean ◽  
Interval Type ◽  
Service State

Facing the important issues of safety analysis and assessment for the train service state, an online quantified safety assessment method based on the safety region estimation and hybrid intelligence technologies was proposed in this paper. First, the previous researches on the safety analysis and assessment were briefly reviewed for the train itself and its key equipment, and the existential problems were further pointed out. Then, using the safety monitoring data and the safety region estimation theory, a new online safety assessment method with data-driven was put forward, which was followed by a detailed description of the concrete implementation steps including the EMD (Local Mean Decomposition) and EM (Energy Moment) based safety risk evaluation index selection, Interval Type 2 Fuzzy C-Means (IT2FCM) clustering based safety region boundary calculation modeling and safety risk grading. Finally, in order to verify its performance through experiments, the above method was applied in analyzing and evaluating service states of the rolling bearings, the key equipment of the train, on the basis of mass field data. The experimental results indicate that this method is valid.

Safety assessment method of steel protective structure against large-scale debris flow

2021 ◽  
pp. 204141962110595
Author(s):  
Hiroshi Kokuryo ◽  
Toshiyuki Horiguchi ◽  
Nobutaka Ishikawa
Keyword(s):  
Debris Flow ◽  
Safety Assessment ◽  
Large Scale ◽  
Assessment Method ◽  
Load Level ◽  
Energy Constant ◽  
Level Ii ◽  
Load Carrying ◽  
Torrential Rainfall ◽  
Protective Structures

Recently, steel pipe open type protective structures (steel open dams) have been damaged because of large-scale debris flow resulting from torrential rainfall based on abnormal climate. This article proposes a safety assessment method for the load-carrying capacity of a steel open dam against large-scale debris flow load (level II load) using the energy constant law. First, the safety assessment method of steel open dams is proposed that the ultimate strength must be larger than the required strength against the level II load, which is determined by using the energy constant law. Second, the load-carrying capacities of three types of steel open dams with different structural shapes against the front and eccentric debris flow loadings are investigated by a push-over analysis. Finally, the safety assessments on load-carrying capacities against the front and eccentric debris flow loading are confirmed and the strength reduction by the eccentric loading is examined for three steel open dams.

scholarly journals Intelligent Safety Assessment of Prestressed Steel Structures Based on Digital Twins

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1927
Author(s):  
Zhansheng Liu ◽  
Guoliang Shi ◽  
Zedong Jiao ◽  
Linlin Zhao
Keyword(s):  
Safety Assessment ◽  
Steel Structures ◽  
Theoretical Method ◽  
Assessment Method ◽  
Construction Safety ◽  
Virtual Space ◽  
Structural Safety ◽  
Space Model ◽  
Digital Twins ◽  
And Control

In the development process of intelligent construction, the safety assessment of prestressed steel structures as an important research direction has become more and more attractive in academia. Digital twins (DTs) is the key technology to realize intelligent construction. The virtual and real interaction of the DTs can provide an efficient management and control mechanism for the construction process. This research proposes an intelligent safety assessment method of prestressed steel structures based on DTs. In this research method, the structural safety assessment is divided into two aspects: performance analysis and maintenance. By analyzing the characteristics of the construction safety assessment, a DTs framework for construction safety assessment is built. Driven by the DTs framework, a physical space model and a virtual space model are constructed. On the basis of virtual and actual interaction, multidimensional information fusion of time and space is carried out to realize the analysis of structural safety performance. On this basis, the paper establishes a Bow-tie model for the maintenance modeling of unsafe construction events. Moreover, the theoretical method formed is applied to the construction of a symmetrical structure (wheel–spoke cable truss). The validity of the method is verified by comparing the cable force calculated by the theoretical method and measured on site. The assessment method driven by the DTs ensures the structural safety and improves the intelligence level of safety management and control of the structure construction.

A novel structural safety assessment method of large liquid tank based on the belief rule base and finite element method

2021 ◽  
pp. 1748006X2110216
Author(s):  
Yuan Chen ◽  
Zhijie Zhou ◽  
Lihao Yang ◽  
Guanyu Hu ◽  
Xiaoxia Han ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Safety Assessment ◽  
Expert Knowledge ◽  
Assessment Method ◽  
Assessment Model ◽  
Structural Safety ◽  
Rule Base ◽  
Belief Rule Base ◽  
Element Method

The structural safety assessment of large liquid tanks (LLT) has attracted an extensive attention. As a typical gray box model, the belief rule base (BRB) model can handle qualitative information and quantitative data simultaneously, which is a suitable modeling tool for structural safety assessment. However, it is difficult to establish and train the BRB model when there is a lack of expert experience and fault samples of LLT. Therefore, a novel safety assessment model for LLT based on BRB and finite element method (FEM-BRB) is proposed in this paper. The FEM is introduced to construct the BRB model by combining expert knowledge and industry standards for the first time, which can effectively compensate for the lack of expert experience. The fault samples are generated in the mechanism simulation model under different working conditions. Based on the fault samples generated by the FEM and historical samples, the projection covariance matrix adaption evolution strategy (P-CMA-ES) optimization algorithm is then used to train the model, which further improves the structural safety assessment accuracy when lacking fault samples. A case study of three actual oil tanks in a coastal port is conducted to illustrate the effectiveness and advantage of the developed structural safety assessment method.

A Novel Safety Assessment Method based on Fault Dependent Matrix

2019 ◽  
Vol 15 (9) ◽  
pp. 2392 ◽  
Author(s):  
Dong Haiyong ◽  
Gu Qingfan ◽  
Wang Guoqing ◽  
Zhai Zhengjun ◽  
Lu Yanhong
Keyword(s):  
Safety Assessment ◽  
Assessment Method

scholarly journals Deformation Inspection and Safety Assessment Method of Buried Flexible Pipeline in Service

2021 ◽  
Vol 1043 (4) ◽  
pp. 042043
Author(s):  
Zhu Xinmin ◽  
Feng Shaokong ◽  
Huang Tao ◽  
Shang Feng ◽  
Yang Lufei
Keyword(s):  
Safety Assessment ◽  
Assessment Method

scholarly journals Development and Validation of a Post-Earthquake Safety Assessment System for High-Rise Buildings Using Acceleration Measurements

Mathematics ◽  
2021 ◽  
Vol 9 (15) ◽  
pp. 1758
Author(s):  
Koji Tsuchimoto ◽  
Yasutaka Narazaki ◽  
Billie F. Spencer
Keyword(s):  
Safety Assessment ◽  
Large Scale ◽  
Model Updating ◽  
Safety Evaluation ◽  
Assessment System ◽  
Shaking Table ◽  
Structural Safety ◽  
High Rise ◽  
Steel Building ◽  
Earthquake Safety

After a major seismic event, structural safety inspections by qualified experts are required prior to reoccupying a building and resuming operation. Such manual inspections are generally performed by teams of two or more experts and are time consuming, labor intensive, subjective in nature, and potentially put the lives of the inspectors in danger. The authors reported previously on the system for a rapid post-earthquake safety assessment of buildings using sparse acceleration data. The proposed framework was demonstrated using simulation of a five-story steel building modeled with three-dimensional nonlinear analysis subjected to historical earthquakes. The results confirmed the potential of the proposed approach for rapid safety evaluation of buildings after seismic events. However, experimental validation on large-scale structures is required prior to field implementation. Moreover, an extension to the assessment of high-rise buildings, such as those commonly used for residences and offices in modern cities, is needed. To this end, a 1/3-scale 18-story experimental steel building tested on the shaking table at E-Defense in Japan is considered. The importance of online model updating of the linear building model used to calculate the Damage Sensitive Features (DSFs) during the operation is also discussed. Experimental results confirm the efficacy of the proposed approach for rapid post-earthquake safety evaluation for high-rise buildings. Finally, a cost-benefit analysis with respect to the number of sensors used is presented.

Structural Safety Assessment of a 1100 TEU Container Ship, Based on a Enhanced Long Term Fatigue Analysis

2014 ◽  
Vol 1036 ◽  
pp. 935-940
Author(s):  
Leonard Domnisoru ◽  
Ionica Rubanenco ◽  
Mihaela Amoraritei
Keyword(s):  
Safety Assessment ◽  
Safety Evaluation ◽  
Irregular Waves ◽  
Structural Safety ◽  
Random Wave ◽  
Wave Loads ◽  
Strength Assessment ◽  
Integrated Method ◽  
Hydroelastic Response

This paper is focused on an enhanced integrated method for structural safety assessment of maritime ships under extreme random wave loads. In this study is considered an 1100 TEU container test ship, with speed range 0 to 18 knots. The most comprehensive criteria for ships structural safety evaluation over the whole exploitation life is based on the long term ship structures analysis, that includes: stress hot-spots evaluation by 3D/1D-FEM hull models, computation of short term ship dynamic response induced by irregular waves, long term fatigue structure assessment. The analysis is enhanced by taking into account the ships speed influence on hydroelastic response. The study includes a comparative analysis on two scenarios for the correlation between the ships speed and waves intensity. The standard constant ship speed scenario and CENTEC scenario, with total speed loss at extreme waves condition, are considered. Instead of 20 years ship exploitation life estimated by classification societies rules from the long term structural safety criteria, the enhanced method has predicted more restrictive values of 14.4-15.7 years. The numerical analyses are based on own software and user subroutines. The study made possible to have a more realistic approach of ships structural strength assessment, for elastic and faster ships as container carriers, in compare to the standard one based only on naval rules, delivering a method with higher confidence in the designed structural safety.

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