Etch pit is a common local etch on inhaul cable. Etch pit on the surface of steel wire can produce pits and lead to the appearance of stress concentration due to geometrical discontinuity in the pits area on steel wire. After studying various stress concentration analysis techniques, it is concluded P-method is the best method suitable for the stress analysis of corrosive pits. The analysis results show that the Von. Mises stress at the bottom centre of pits and stress concentration factor in the pit first decreases and then increases with the depth increase of the pits. In the research on steel wire fatigue life, when paying attention to the maximum stress value, it still needs to consider the etch degree on steel wire section. The calculated data lay a certain foundation for the life study of inhaul cable.
<div>With the development of automotive intelligence and networking, the communication architecture of automotive network is evolving toward Ethernet. To improve the real-time performance and reliability of data transmission in traditional Ethernet, time-sensitive network (TSN) has become the development direction of next-generation of automotive networks. The real-time advantage of TSN is based on accurate time synchronization. Therefore, a reliable time synchronization mechanism has become one of the key technologies for the application of automotive Ethernet technology. The protocol used to achieve accurate time synchronization in TSN is IEEE 802.1AS. This protocol defines a time synchronization mechanism suitable for automotive Ethernet. Through the master clock selection algorithm, peer link delay measurement, and clock synchronization and calibration mechanism, the time of each node in the vehicle network is synchronized to a reference master clock. In addition, the protocol clearly states the requirements for node synchronization accuracy in the vehicle network. In this article, it is proposed that an automated test methodology for time synchronization mechanism in the case of multi-device network topology for the IEEE 802.1AS protocol in TSN is applicable to in-vehicle environments. The test methodology automates the process of achieving time synchronization and automatically tests the time synchronization mechanism. In addition, a corresponding test system was designed and developed, and a physical test platform was built to physically test and verify the time synchronization mechanism of the protocol. The results show that the test method proposed can realize the automated testing of the time synchronization mechanism in the case of automotive Ethernet networks. The presented results can contribute to the practical application of automotive TSN technology.</div>
The development of intelligent networked vehicles has put forward the requirements of high bandwidth, high real-time and high reliability for automotive network communication. Time sensitive network has become an important research content of vehicle Ethernet because of its high-precision synchronization, deterministic delay, redundant communication and other characteristics. This paper proposes an instruction delay time model in vehicle-mounted scenarios, and based on OMNeT++ simulation platform and improved CoRE4INET framework, combined with vehicle-mounted network traffic scenarios, designs network topology and simulation traffic, simulates and analyzes the performance of Cyclic Queuing and Forwarding (CQF) mechanism, and compares it with Time Aware Shaper (TAS) mechanism. The simulation results show that compared with Time Aware Shaper mechanism, the Cyclic Queuing and Forwarding mechanism has better performance for aperiodic messages in the vehicle-based scenario designed in this paper, and can effectively reduce the end-to-end delay of messages.
The low cycle fatigue (LCF) behavior of high-strength structural steel under biased strain control has been investigated. Seven strain ratios with constant maximum strain amplitude were adopted. Significant cyclic softening and mean stress relaxation were observed in all cases. The fatigue life under biased strain control could be well predicted by Coffin-Manson relationship. Fractography by scanning electron microscopy was used to determine the LCF failure mechanisms and fatigue crack propagation modes.
Method of discount quality is always used in calculating the natural vibration period of tower in the design of tower. When tower's cross-section is variable, the calculating formula is complex, and big workload. Thus, this method is cramped in actual engineering. In view of the powerful function of ANSYS, the secondary development of ANSYS is worked with the method of discount quality in this paper. It's efficient in calculation, accurate in results, and simple in use. It is essential to increase the work efficiency in the design of tower.
The low cycle fatigue (LCF) behavior of Q235 steel under mean strain control has been investigated. A serious of the strain controlled cyclic loading experiments with several combinations of strain amplitudes and mean strains have been performed. Significant cyclic hardening and mean stress relaxation were observed in all cases. Fractography by scanning electron microscopy (SEM) was used to determine the LCF failure mechanisms and fatigue crack propagation modes of the Q235 steel.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)