Finite Element Analysis and Test of Braze Residual Stress Between Different Materials
Liu Shichao,
Pang Xueman,
Zhou Hao,
Cheng Kai
Issue:
Volume 7, Issue 3, June 2019
Pages:
75-81
Received:
21 May 2019
Accepted:
2 July 2019
Published:
12 July 2019
Abstract: To assess the rationality and reliability of the finite element model, finite element analysis and test were performed on the braze residual stress between two materials with different expansion coefficients. The samples used in this paper were obtained by welding tungsten - copper wafers and kovar wafers. The finite element analysis method and stress testing method are introduced briefly. In order to describe the welding process, this paper uses several related equations to illustrate the simulation calculation, and introduces the complex analysis process of the test method, and briefly introduces the processing method of the test data. The test results mainly include the residual stress values corresponding to different depths on the drilling path, and the stress state at this position is expressed by tensile stress and compressive stress. The results of finite element simulation analysis are comprehensive. In order to compare with the test results, the direction and size of tensile stress and compressive stress of the section are selected. The results of test are consistent with those of finite element analysis. It was suggested that the residual stress obtained from the finite element model is feasible and can be referenced to understand the residual stress of the actual devices. Then an example is given to verify the consistency of the two methods.
Abstract: To assess the rationality and reliability of the finite element model, finite element analysis and test were performed on the braze residual stress between two materials with different expansion coefficients. The samples used in this paper were obtained by welding tungsten - copper wafers and kovar wafers. The finite element analysis method and str...
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New-age Supercomputers: Hi-Speed Networks and Information Security
Issue:
Volume 7, Issue 3, June 2019
Pages:
82-86
Received:
18 August 2019
Accepted:
21 September 2019
Published:
9 October 2019
Abstract: The author describes computing strategic tasks that are used for ensuring defense and national security, the most important scientific, technical, biomedical and sociology tasks. Most typically, these are capability-based tasks. Supercomputers for their solution are respectively called Technical Capability, i.e. machines of extreme technical capabilities. Machines of this segment are also called High End Computers (HEC), and in our terminology - strategic supercomputers (SCs). Moving to the engineering level, author says that for tasks with good spatio-temporal work with memory, cache memory and schemes for automatically pre-loading data into the cache memory can be effectively used. This can significantly reduce the average memory access time of several hundred processor cycles to fractions of a processor cycle. Such tasks are usually called computational or cache-friendly (cach-friendly) - CF tasks. On tasks with poor spatio-temporal work with memory, the cache memory is useless, so each memory access is hundreds of processor cycles, the processor is idle because of this, and therefore the real performance is in units or even a fraction of a percent of the peak. Such tasks are historically called tasks with intensive irregular work with memory – Data intensive tasks (DIS-tasks). The given examples of spatially-temporal work with task memory and real characteristics of equipment operation in such different modes are given in order to illustrate that in practice different types of supercomputers are needed, for example, for CF- and DIS-tasks.
Abstract: The author describes computing strategic tasks that are used for ensuring defense and national security, the most important scientific, technical, biomedical and sociology tasks. Most typically, these are capability-based tasks. Supercomputers for their solution are respectively called Technical Capability, i.e. machines of extreme technical capabi...
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