Applied Mechanics and Materials Vols. 635-637

Abstract: At the current level of technical development of subsea pipeline systems a probability of their damage during construction and operation due to various causes may not be excluded.In the regions of high seismic activity the soil destruction may occur in the weak layers forming seabed deformations. Hazard management practice has advanced in recent years, due to several factors: global pipeline expansion in areas of difficult terrain (tectonic/seismicity; permafrost area, landslides) coupled with a greater understanding of the prevalence of hazard.Formal risk assessment is relatively immature in most industries, including pipelining. A better solution is to establish guidelines of essential ingredients necessary in any pipeline risk assessment. Critical would be identified and it would be left to the operator subject matter experts to detail those elements.This article focuses on the problem of imposing special (seismic) loads; the subject matter of the article also includes the issues of the marine pipeline safety (risk) evaluation.

Abstract: The joint clearance and contact phenomena are the key factors which can induce the nonlinear dynamic responses and affect the performance of the practical mechanism. It is difficult to solve the nonlinear relations between the input variables and responses when the random factors are considered. In this paper, three approximation models, i.e., Response Surface Model (RSM), Kriging model and Support Vector Machine (SVM), are selected to investigate the reliability analysis procedure by the combination of simulation technique and approximation model for the mechanism with joint clearance. The solution strategy with supplemental samples is proposed to solve the problem caused by the occurrence of the abnormal point in the iteration procedure, and to avoid the divergence in the reliability analysis caused by the nonlinear dynamic responses of the mechanism. Meanwhile, the computational consumption can be reduced as the results of the known samples are reused. Finally, the reliability analysis for a slider-crank mechanism with joint clearance is utilized to illustrate the proposed procedure.

Abstract: The accidents of ship oil spill have been one of the most significant factors leading to marine pollution, so appropriate approaches to forecast ship oil spill risk has important significance. Risk assessment of ship oil spills is a complex multi-factor issue, which plays a key role of ship oil-spill emergency response. A novel fuzzy evaluation model for risk assessment of ship oil spill is presented by analyzing historic accident data and expert experience. The model is used to compute comprehensive accident probability of ship oil spill and analyze sensitivity of risk factors so as to evaluate ship oil spill risks quantitatively and find out major risk factors which influedce ship oil spill risk. At last, the presented model is applied to study the ship oil spill risk in Ningbo-zhoushan port, the assessment examples are proved to test the feasibility and reliability of the model.

Abstract: Main Pipelines of the Russian Federation are critical energy facilities that make a significant contribution to the operation of power industry as a whole. Earthquakes are almost always followed by an increase in the accident rate on pipelines. Therefore, there is a reason to suppose that seismic forces (even minor ones) accelerate failure occurrence in a number of pipeline sections and serve as “the last straw” that causes accidents. The pipelines incur the most severe damage when the route is co directional to the seismic strain vector.

Abstract: This article provides a comprehensive post hoc analysis on the explosion of horizontal cold-chamber accumulator occurred in a company in Hangzhou in May 2014, which is considered as a pressure vessel explosion accident, but not a special equipment accident, and is thus determined as a production safety accident. Based on detailed analysis of working principle of horizontal cold-chamber die-casting machine, the article puts emphasis on working principle of bladder accumulator and deduces two possible causes of accident through thickness measurement, metallographic test, explosion energy estimation and mechanical test on the faulty accumulator. On the basis of accident analysis, the article presents that great importance should be attached to the safety in inflation of accumulator of die casting machine, to prevent similar accidents from happening again by improving the operation system.

Abstract: With the arrival of China's oil and gas pipeline network era, the security of oil and gas pipelines confront great challenges. Scientific pipeline safety management methods and concepts are needed. In this paper the SHEM model which is composed of hardware, software, environment and management is put forward to explain the cause of oil and gas pipeline accident. According to the control system of management failure, the oil and gas pipeline accident model based on failure of generalized management is established to provide effective methods for accident prevention and construction of safety management system for oil and gas pipeline.

Abstract: Based on reliability theory, fault information is used to research the rule of fault and analyze reliability. To disadvantage of normal methods, the method of linear transformation of non-linear regression model to fit distribution to determine the best distribution is proposed. It can solve the problem with normal method is affected by experience and without compare. The result shows the model works effectively.

Abstract: The paper addresses a modelling procedure to automatically generate 2D finite element meshes of tires, together with the assignment of material property. A program is developed based on the secondary development of HyperMesh with TCL/TK language, thus achieving the automatic FE modelling starting from the AutoCAD tire cross-section profile. The model created as input file can be exported into ABAQUS directly. By automatizing the modeling process, the program can significantly reduce the modeling time and improve modeling efficiency.

Abstract: In this paper, we have presented a method to generate efficient NC tool paths based on the surface subdivision. The main objective is to achieve high efficiency in the machining of sculptured surface. The NC machining efficiency can be improved by segmenting the whole surface into distinct areas according to the characters of sculptured surface and by using different size mills and different tool path planning methods to machine the areas. The iso-parametric method and large mills are used in the curvature changing little areas. While the iso-scallop method and small mills are used in curvatures changing large areas. This can make full use of tool path generation methods and mills, which improve the machining efficiency of sculpture effectively.

Abstract: In order to improve the efficiency of the calculation of the whole car side impact finite element model,simplified model often used in research of B-pillar in passenger car. It is critical to establish a high accuracy simplified model in a short time. The relationship between the energy absorption of body parts and the calculation accuracy of simplified model was analyzed,and the result can be used as a guide for the establishment of simplified model.