This study investigates recurrent leakage failures that occurred at nearly identical locations in 1Cr18Ni9Ti stainless steel pipes from multiple aircraft. Surface analyses reveal characteristic damage features: an inner-surface 'valley' with honeycomb-like craters and facets, contrasting with a single outer-surface perforation. The failure process involves progressive pit initiation, followed by the nucleation and multidirectional growth of fatigue cracks. Cavitation erosion is identified as the primary failure mode, whereby cumulative bubble collapse progressively reduces wall thickness. Simulations using AMESim and oil-gas two-phase flow models demonstrate that a sudden pressure drop creates low-pressure regions and promotes gas accumulation on the inner side of the pipe bend. These findings are consistent with the observed failure location and mode. Optimized design modifications are proposed and validated to enhance cavitation resistance of the pipe and prevent such failures.

The highly reliable new generation substations of SGCC have the characteristics of independent controllability, safety and reliability, advanced applicability, and intensive efficiency. They are currently the preferred technical route for smart substation renovation. However, traditional smart substations have significant differences from the new generation substations in terms of network system topology, secondary equipment configuration principles, and message compatibility of the process level. This article proposes the design principles of a secondary information conversion device that realizes compatibility conversion between electrical and digital information interfaces, as well as the implementation process of the new generation substation secondary system renovation. For substations that use various sampling tripping and network schemes, secondary circuit technology schemes and highly reliable network topology structure for the secondary system during the reconstruction are proposed, ensuring the independence of the dual network and the integrity of the data flow. To ensure that a single network anomaly does not affect the normal operation of other networks, the data flow control technology adapted to different network topologies is proposed.

In this work, we test the performance of an exact-factorization-based density functional approximation (DFA) for electron–nuclear correlation beyond the Born–Oppenheimer approximation that was derived in Li et al. [J. Chem. Phys.148, 084110 (2018)]. The present work extends beyond the Hubbard model that was used previously in a two-electron Shin–Metiu model with continuous electronic density in one dimension. Using new iteration techniques, we managed to solve coupled Kohn–Sham equations that embody nonadiabatic corrections with a nuclear Schrödinger equation. Our results show that the DFA can successfully capture the nonadiabatic effect caused by electron–nuclear correlation as manifested in the correct shift of the critical nuclear position where the proton-coupled electron transfer takes place. The nonadiabatic correction to the Kohn–Sham potential also leads to a shift of orbital energies, which can potentially be useful to study band renormalization induced by electron–phonon interactions in bulk materials.

1Cr17Ni2 martensitic stainless steel has good corrosion resistance and mechanical properties, and thus it is widely used in corrosion-resistant and load-bearing parts. After the machining process, commercial 1Cr17Ni2 steel components are usually solution treated and tempered under vacuum condition to achieve higher strength as well as dimensional accuracy. However, severe premature corrosion of 1Cr17Ni2 steel components is always correlated with a white layer formed during the heat-treatment process on the surface. In this study, the 1Cr17Ni2 alloy samples were solution treated at 950.C for 90 min by practical commercial vacuum furnace with the pressure of 13.3-26.6 Pa, followed by furnace cooling instead of oil quenching. The microstructure and local elemental distribution of the white layer on the surface of a 1Cr17Ni2 steel were characterized in detail by scanning electron microscopy, backscattered electron diffraction, scanning transmission electron microscopy and three-dimensional atomic probe. The sample surface transformed to a similar to 15 mu m thick white layer of austenite phase with fine particles rich in Cr and C atoms, which is different from the inner matrix containing a mixture of martensite and d-ferrite. Elemental distribution showed a depletion of Cr and enrichment of C atoms in white layer compared with the matrix. This could expand the austenitic region, resulting in retained austenitic microstructure on the surface. In addition, since Cr elements were consumed locally, the corrosion resistance of the steel with white layer decreased significantly, as proved by salt spray test and intergranular corrosion resistance test. These microstructure observations and the elements distribution were interpreted consistently by carburizing from the contaminated commercial vacuum furnace.

在原有的组装集箱制造工艺的基础上,又经过多个项目的生产实践,通过对组装集箱生产制造过程中出现的问题进行分析和总结,对其制造工艺进行了一些改进和优化,主要体现在对组装集箱装配工装的抗热处理变形能力和不锈钢拉撑定位板进行了改进,对管端的修正余量和管端复加工刀具进行了优化,对相应的部分制造工艺进行了调整.

The invention provides a dot matrix structure dynamics response optimization design method for additive manufacturing. The method comprises the steps that an energy method is used for calculating theequivalent mechanics performance of a single-cell structure, and a proper single-cell configuration is selected according to different loads; multi-point constraints (MPC) are adopted for being connected with concentrated mass so that the multi-point acceleration is excited and converted into force motivation, and a modal displacement method is adopted for calculating structure displacement response; finally, by considering the minimum manufacturing dimension constraint of the additive manufacturing technology, design is performed by adopting the minimum dot matrix designated position displacement response as a target. Compared with a design method in the prior art, equivalence is performed on the mechanical performance of the dot matrix single-cell structure, dynamics response characteristics of the dot matrix structure are considered, the given structure configuration dot matrix can be designed, and therefore the requirement for engineering application is met.

Presented in this paper is a method for the design of modular reconfigurable machine tools (MRMTs). An MRMT is capable of using a minimal number of modules through reconfiguration to perform the required machining tasks for a family of parts. The proposed method consists of three steps: module identification, module determination, and layout synthesis. In the first step, the module components are collected from a family of general-purpose machines to establish a module library. In the second step, for a given family of parts to be machined, a set of needed modules are selected from the module library to construct a desired reconfigurable machine tool. In the third step, a final machine layout is decided though evaluation by considering a number of performance indices. Based on this method, a software package has been developed that can design an MRMT for a given part family.

Due to the presence of dependence linkages, changing one element of a product (e.g., functions and components) can trigger changes to other related elements and lead to numerous possible propagation paths (i.e., the “snowball effect”). To address this issue, this paper proposes the matrix-based clustering method. Two matrix models are considered in this research: design structure matrix for the linkages of components and domain mapping matrix for the linkages of functions and parameters. After denoting some product elements as “target” representing the initial changes, the clustering method is used to form and classify the clusters according to the change impacts from target elements. The interfaces between the clusters are also identified to manage the propagation process. The purpose of this method is to provide the cluster and interface information for implementing change requests. In view of the methodical advancement, the clustering method can tailor a clustered matrix for specific change requests and handle two types of matrices. Two examples have been used to demonstrate and support the utility and flexibility of the proposed method to manage matrix-based change propagation.

On the basic of analysis on characteristics of large complex projects, this paper thinks that the optimize production processes of large complex project is necessary, and introduces the following three key technologies- the WBS, the fast-tracking and the branch-bound method, which used to achieve process optimization. The WBS is for process decomposition, the fast-tracking is for logic rearrangement of process, and the branch-bound method is for the cost optimization of the local Process duration estimating.

The portable low-intensity x-ray real-time imaging system was composed of Lixiscope, the image collection and procession system of CCD. Recently, people pay more attention on it due to its wide applications. In this paper, the structure and characteristics of CsI/MCP photocathode was briefly given. The controllable main factors (image noise and aberration) which influence the imaging quality of the image tube (single single-proximity focusing x-ray image intensifier) were analyzed. The method to improve the image quality by decreasing the working voltage of MCP was proposed. At the same time, the other method such as cooling CCD, prolonging the integration time and image-processing were also studied. The optimized resolution (6.31p/mm) was obtained which can achieve the anticipated goals to decrease the flashing noise and ensure the brightness of the image. Using this system; the industrial product, the finger of human body and so on can be detected and diagnosed. The corresponding pictures were given which indicating an wide applications of this new type of low-intensity x-ray real-time imaging system.

The structural principle of UV photoelectric method for the measurement of the multiplied characteristics of two dimensional electron multipliers and the simulation of the dynamic characteristics of the image-tube were given in this paper. It was shown that the choice of surface electron source with a uniform current density is the key point. Using this method, the electron gain and the transmission characteristic of the MCP (or the MCP with an ion barrier film) were measured. The relationship between the dead-voltage and the thickness of the ion barrier film and it's applications were given. For the first time, the concept of "equivalent cathode" was proposed. The test principle of UV excitation method for double MCP performance was shown in detail; in this method, the obtained electron emission from MCP1excited by the UV source replaced that electrons from Au thin film, and using these electron emissions to measure the performance of another MCP2. The application prospect of this method on the measurement of the ions transmission and stopping characteristic though the ion barrier film were shown.

This paper describes our continued effort in the development of the model-based rapid redesign methodology. In the prior work (Chen et al. in ASME J Mech Des 129:283–294, 2007), we have explored and applied various decomposition patterns for rapid redesign to effectively control design change propagation. Since the decomposition process for redesign is not activated until the presence of a redesign request, this prior work represents a reactive approach where a new set of decomposition patterns should be generated in accordance with a different redesign request input. As an extension to our redesign methodology, this paper presents a proactive approach to complement the existing methodology for rapid redesign. In this approach, the decomposition patterns capturing generic decomposed structures of a given design model are created in advance and stored in a design library before any redesign request emerges. These pre-generated patterns are able to address any upcoming redesign request without further decomposition procedures in redesign. This proactive approach is developed in a new framework of pattern-based reasoning that is built on the mechanism “case → pattern → strategy.” Two methodological components, Proactive Redesign Decomposition and Redesign Condition Analysis, are introduced along with a redesign application to an existing air-cooled condenser for illustration. This redesign approach is particularly useful when it requires only minor yet frequent modifications for the existing design.

In literature, design structure matrix (DSM), which is a square matrix, has been widely used to address single-domain dependency relationships (e.g., product architecture, process workflow, and organization structure). To extend the DSM efforts, a rectangular matrix becomes a logical format to capture and analyze cross-domain dependency relationships, namely, domain mapping matrix (DMM) [1]. In this context, this paper proposes a unified framework for decomposition of DSM and DMM. The unified framework consists of four methodological phases to offer the functions of DSM clustering, DSM sequencing, and DMM decomposition. To support the development of this framework, various decomposition-related techniques from applied mathematics and engineering design are reviewed. Three matrix examples have been used to illustrate the framework's applicability.

In this paper, the noise and optical aberration which were two controllable factors that affect the image quality in the single-proximity-focusing x-ray image-intensifier were studied. By decreasing the electron gain of microchannel plate (MCP), the noise of the x-ray image-intensifier can be decreased. The optimal operating condition for the image intensifier and the CCD were also investigated. Based on this investigation, the flash-noise of the x-ray image-intensifier can be decreased and the brightness of the image can be improved. At the end of the paper, some results on the image-capturing of the cool CCD with low noise were presented.

Taking Millar garden,fountain square and AG headquarters building garden as examples,the author analyzes the main characteristics of Kiley's design thoughts,illustrates his design methods of skillfully using geometric order,space infiltration and design elements to create harmony,and introduces his harmonious life,in order to let people know more about him and his design thoughts.

This paper presents a pattern-based decomposition methodology for rapid redesign to support design customization in agile manufacturing of evolutionary products. The methodology has three functional phases. The first phase, called design dependency analysis, systematizes and reorganizes the intrinsic coupling structure of a given existing design model that is represented using the design dependency matrix. The second phase, called redesign partitioning analysis, generates alternative redesign pattern solutions to form a solution selection space through a three-stage procedure. The third phase, called pattern selection analysis, finds an optimal redesign pattern solution that entails the least potential redesign effort (in the subsequent solution process). Each pattern solution identifies and delimits the portions of the design model that need to be recomputed, thus expediting the redesign solution process. In such a way, one can treat the recomputation of the entire model, which is a conventional and computation-expensive solution approach, only as the last resort to solve the redesign problem given. An example redesign problem is used for the methodology illustration.

Critical Parameter Management (CPM) is an emerging area in engineering design owing to the motivation from Design for Six Sigma. Introduced in this paper is the exploration of CPM to support rapid redesign of evolutionary products in the context of mass customization. Along this line, a model-based CPM method that utilizes and leverages matrix patterns to support rapid redesign is presented, discussed and illustrated through the use of a redesign example as a case study. In particular, proposed in this paper is the pattern-centric CPM approach to rapid redesign based on “case → scenario → pattern → strategy → roadmap” reasoning mechanism. The results show that the proposed method enables one to rapidly reconfigure or customize the existing design of a given model as well as the promising future of this emerging research. This work represents an extended effort to complement our ongoing research on developing decomposition-enabled techniques to support model-based rapid redesign.

The two-phase method for model-based decomposition (Chen et al. 2005a) has two major functional components: dependency analysis and partitioning analysis. The functions of these two components are enhanced and generalized in this paper in order to improve the method’s capability. On the one hand, the non-binary dependency analysis is developed such that the two-phase method can handle both binary and non-binary dependency information of the model. The essence of this development is to properly select a resemblance coefficient for the quantification of couplings among the model’s elements. On the other hand, as the past version of partitioning analysis takes the enumerative approach to search decomposition solutions, the heuristic partitioning analysis is developed as an alterative to search a reasonably good solution in a shorter time. The working principle of the heuristic approach is to analyze the coupling structure of the model such that the weak coupling links among the model’s elements can be identified for model partitioning. At the end, a relief valve system is applied to illustrate and justify the newly developed method components.

This paper attempts to explore different models of multi-team-based design optimization in a cooperative computing environment. To deal with multi-team design, a framework consisting of four mapping constituents (i.e. design decomposition → goal formulation → preference modelling → satisfaction aggregation) is suggested and elaborated together with the related solution strategy. In this framework, three cooperative team design models are proposed to characterize and account for typical schemes of cooperation in design computing. Related algorithms are also presented to facilitate executing these models. To validate the cooperative design models, an example of heat exchanger design is worked out illustratively. The results further show how different schemes of cooperation in multi-team design affect the final design solutions.