Application of the concept of criterion of a complex stress state to a simple tension for appraisal of resistance of fatigue of structural materials. Part 2. Drawing up criterion and its checking on compliance to experimental data

The criterion for appraisal of resistance of fatigue of structural material at action on it of repeatedly variables loads and static loads in the form of a bend or tensioncompression together with torsion, and also at action of loads, which create two-axis regular change of stress state in a dangerous point of material is constructed. The received criterion will acceptable be coordinated with the known experimental data. Keywords: dangerous point of material, regular cycle of loading, equivalent amplitude, equivalent average stress, chart of extreme amplitudes of stresses. [email protected]

Lessons Learned of Tehran-Zahedan Train Derail, Iran, 2019

Background: There has been a significant increase in the number of train crashes worldwide, mainly due to the extension of the rail network and the use of the most sophisticated and cutting-edge technology. Incident Report: The Tehran-Zahedan train had 260 passengers on board and left for Tehran City at 14:50 local time on Wednesday, September 25, 2019. The accident happened at 16:20 local time at 100 km distance from Zahedan City. Results: Five train cars derailed 2 km from Shorou Station, where four people died, and 157 were injured. According to the investigations, the accident occurred due to the unscrewing of some bolts and spring washers. There were 170-180 screws and spring washers removed along 50-60 m, which resulted in the creation of a dangerous point and derailment of the train. This study examined the challenges, strengths, and learned lessons of the incident. Conclusion: Concerning standard and vast rail networks in Iran and the latest train crashes that mainly occurred just outside the cities, accessibility to the accident scene should be considered one of the most important physical vulnerability indexes. As a result, accessibility to special firefighting and rail rescue train car at some stations in crowded routes effectively decreases the consequences of such accidents.

Investigation on Aircraft-store Compatibility Criteria of External Store Separation

The evaluation of aircraft-store compatibility on external store separation is a key issue in the separation system of vehicle design. Firstly, the aircraft-store compatibility criterion of an external store separation is put forward, and then the criterion is converted to an unequal relationship between velocity and acceleration in vertical displacement and pitch angle based on the constant force assumption, which is validated by the test result of wing pylon finned store model (WPFS). The three-dimensional compressible Reynolds average N-S equation and rigid body six-degree-of-freedom motion equation (6-DOF) are solved by using unstructured dynamic overlap grid technology, to obtain the kinematic parameters of the external separation. Finally, the most dangerous point M on the tail of the external store is selected to verify the aircraft-store separation criterion. The results show that the kinematic parameters of the most dangerous point M on the tail wing of the store fall in the safe separation area, which means that the complete separated process is safe.

China’s National Experiences and the Evolution of PRC Grand Strategy

This chapter focuses on the People’s Republic of China’s “grand strategy” in world affairs. Grand strategiy, for all powers, is rooted in the nation’s past and its historical evolution. As such, this chapter traces the various historical and cultural sources of China’s contemporary approach to the world. It argues that China has a deep sense of greatness—but also wounded pride. In particular, different sources of China’s traditions, encounters with the West, border insecurities, and preoccupation with the United States. The author argues that China’s relations with the United States are reaching a critical, and dangerous, point.

Research on wooden window nodes of optimal design

Mortise connection is a unique way of connection in the wood structure of ancient buildings in China. This paper takes the mortise and mortise joints of wood window frame as the object. Eight models of wooden window frames are built in ANSYS software with the parameters of tenon diameter and tenon length. The static performance of them is studied. Through simulation loading, the ultimate bearing capacity of the model under vertical and horizontal loads is obtained, and it is concluded that the Mohr strength of the dangerous point and the maximum displacement value at the contact of the mullion and mullion are linearly related to the applied load. Through the parameter analysis, such as the diameter and length of mortise and tenon joint, the optimal design of this kind of mortise and tenon joint component are carried out so as to provide the theoretical basis for its application in the actual project.

Penurunan Jumlah Lahan Dan Perubahan Budidaya Tanaman Kopi Bali Kintamani Mengancam Destinasi Wisata Kopi Di Kintamani

This research is conducted in Catur Village, Kintamani District, Bangli Regency. The purpose of this research is to identify the decreasing number of coffee land of Kintamani Bali Coffee plantation and its causes. The data used in this research are qualitative and quantitative, while the data of this research consists of of primary and secondary data. The data is collected through observation, depth interviews, and documentation. The informants are determined through purposive sampling procedure, and they are I Ketut Jati (Head of Masyarakat Perlindungan Indikasi Geografis Kintamani) and Kocong Neca (Local Coffee Farmer). Afterward, the data that has been found is analyzed by descriptive qualitative method. The results of this research show that the decreasing number of coffee land of Kintamani Bali Coffee plantation on has reach its dangerous point and threaten tourism in Kintamani. In the last two years, the number of coffee land of Kintamani Bali Coffee had decreased significantly from 6.335 Ha to 4.772 Ha and automatically causing the total production of Kintamani Bali Coffee beans dropped from 2.314 Ton to 2.046 Ton. The biggest reason of the decreasing number of coffee land came from land conversion. The difference of income between coffee plantation with orange plantation also made farmers in Desa Catur to shift to grow more orange than coffee. In a 0,5 Ha field, orange plantation could gain profits approximately for Rp 114.945.000, while coffee plantation only gain profits for Rp 63.530.000. Moreover, plant-paracitic nematodes are damaging the coffee plantation. Therefore, the number of lands to grow coffee are decreasing. The recomendation from this research addressed to government service of Agriculture, Plantation and Forestry Bangli to keep oversee Kintamani Bali Coffee plantation and give an aid towards the Nematoda Parasite Diseases problem. Furthermore, farmers required to improve their human resource’s skill, so they can use management system on their plantation. Keywords: Land Degradation of Plantation, Change of Plant Cultivation, Kintamani Bali Coffee, Coffee Tourist Destination, Kintamani District

The application of the principles of the theory of shakedown to the calculation of pavement layers of granular materials in shear

In the report ways of application of the theory of shakedown of material to calculation of coverings and the bases of pavements from the granulated materials are considered. The basic limits of shakedown are given, which include the limits of resilient, elastic and plastic shakedown. The results of three-axis tests are given, on the basis of which the character of accumulation of residual deformation is divided into damped, steady and progressive. These data allow to predict the nature of deformation and provide damped deformation of the granular material, limiting the stress at the most dangerous point.

A convex model approach for structure non-probabilistic reliability analysis

In this article, a novel approach, that is, convex model method of set theory, is proposed to investigate the non-probabilistic reliability of bridge crane. Considering the metal structure system of the bridge crane, the finite element method is applied to obtain the stress response of the structure dangerous point. Then, the sample of stress response of the structure danger point and uncertain parameters are obtained. Finally, based on support vector machines, the structure implicit regression function of the system is replaced by explicit expression that calculates the non-probabilistic reliability of the structure. Results show that this approach is useful and efficient to solve the problem of non-probabilistic reliability in the metal structure.

Ratcheting Behavior of Pressurized Elbow Pipe under Different Loading Modes

Ratcheting deformation is studied on elbow pipe made of Z2CND18.12N by FEM software. The simulation is conducted by ANSYS. Chen-Jiao-Kim (CJK) kinematic hardening model is added in ANSYS for the study. The elbow pipe is subjected to internal pressure and reversed in-plane bending. Internal pressure can be constant or cyclic. Many different loading paths are used in the study. Ratcheting deformations of under different ways are studied. The result shows that ratcheting deformation occurs mainly in the circumferential direction. Ratcheting deformation at the crown and intrados of elbow pipe is more notable because of higher stress. Tensile or compressed load can influence the position of dangerous point. It is found that ratcheting deformations under different paths with same peak load are different.

Contact Stress Analysis and Fatigue Life Prediction of a Turbine Fan Disc

Fan discs are critical components of an aero engine. In this paper, contact stress and life prediction of a turbine fan disc were investigated. A simplified pin/disc model was conducted to simulate the practical working condition under applied loads using finite element (FE) analysis. This study is devoted to examining the effects of interface condition of pin/disc such as gap and coefficient upon the maximum stress. The FE model indicated that the maximum stress occurs at the top right corner in the second pin hole, and larger gap or friction coefficient has a significant effect on the maximum stress. In addition, FE analysis without considering friction is also conducted. The results show that the dangerous point is similar to the result which considers friction and the stress state is relatively larger than that of considering friction. Finally, based on FE analysis result, life prediction for the fan disc is conducted to combine the material