RESEARCH ON THE INFLUENCE OF MILD STEEL DAMPERS ON SEISMIC PERFORMANCE OF SELF-RESETTING PIER

In order to improve the energy consumption capacity of the assembled self-resetting pier, the mild steel damper is added to the prefabricated self-resetting pier to form a prefabricated self- resetting pier with an external mild steel damper. Two sets of pier models were established by numerical simulation. On the basis of verifying the correctness of the traditional prefabricated self- resetting pier model, the two sets of pier models were subjected to low-cycle reciprocating loading to study the influence of the mild steel damper yield strength parameters and the pier axial compression ratio parameters on the seismic performance of the pier structure. The results show that compared with traditional prefabricated self-resetting piers, the hysteresis curve of self-resetting piers with mild steel dampers is fuller, and energy consumption and bearing capacity are greatly improved. With the increase of the yield strength of the mild steel damper, the energy consumption capacity will decrease when the loading displacement is less than 25mm, but the overall energy consumption capacity will increase. As the axial compression ratio of the pier column increases, the bearing capacity and energy consumption capacity of the structure increase significantly, but the impact is not obvious when the axial compression ratio exceeds 0.052

Coordination mechanism of SaaS service supply chain: based on compensation contracts

Purpose: The purpose of this paper is to build new contracts theories of SaaS service supply chain. Software as a Service (SaaS) has become a hot topic in this industry . Compared with traditional manufacturing supply chain and general service supply chain, the new IT service supply chain which based on SaaS has characteristics of both service and IT. And SaaS is completely different from traditional software package model. Therefore the classic contracts, which be widely used in traditional manufacturing supply chain, can’t be directly applied in SaaS service supply chain. The necessary way of IT services developing is to study the SaaS service supply chain combining with characteristics of SaaS. Therefore, It focuses on the coordination of SaaS service supply chain. Design/methodology/approach: It tries to answer the following question: how do the ISV motivate SaaS operators to improve the service level through effective contracts mechanism under conditions of asymmetric information. In order to answer these questions, this paper does some researches including: Under the conditions of information asymmetry, supposing the service level (is related to the degree of effort) of SaaS operator was private information, we construct model of compensation contract, i.e., to motivate SaaS operator to improve service level through transfer payments of compensation price. Findings and Originality/value: The study finds out that when ISV get to “positive feedback”, instead of the traditional market equilibrium, compensation contract (linear) can coordinate satisfactorily the SaaS service supply chain. In the point of “positive feedback”, the marginal revenue equals the marginal cost, but it is not the equilibrium of ISV’profit-maximization. Research limitations/implications: There are some limitations in this research. In the linear compensation contracts, the compensation price is fixed value. If in the contract, we can create a change value which is related to the sales volume of service, the coordination efficiency of compensation will be increased. And in the future, the nonlinear compensation contracts should be researched. Practical implications: In the practical implication, it will promote the development of study and practice of SaaS and IT service industry. And it is beneficial to ISV, platform operators and customers. Originality/value: From the theoretical perspective, this paper put forward some new contracts and motivating mechanism for effective coordination of SaaS service supply chain and the conclusion will enrich content of service supply chain theory system. In theory, it has more significance for further researching on SaaS and service supply chain.Peer Reviewe

Characterization of particle number concentrations and PM2.5 in a school: influence of outdoor air pollution on indoor air

Background, Aim and Scope The impact of air pollution on school children’s health is currently one of the key foci of international and national agencies. Of particular concern are ultrafine particles which are emitted in large quantities, contain large concentrations of toxins and are deposited deeply in the respiratory tract. Materials and methods In this study, an intensive sampling campaign of indoor and outdoor airborne particulate matter was carried out in a primary school in February 2006 to investigate indoor and outdoor particle number (PN) and mass concentrations (PM2.5), and particle size distribution, and to evaluate the influence of outdoor air pollution on the indoor air. Results For outdoor PN and PM2.5, early morning and late afternoon peaks were observed on weekdays, which are consistent with traffic rush hours, indicating the predominant effect of vehicular emissions. However, the temporal variations of outdoor PM2.5 and PN concentrations occasionally showed extremely high peaks, mainly due to human activities such as cigarette smoking and the operation of mower near the sampling site. The indoor PM2.5 level was mainly affected by the outdoor PM2.5 (r = 0.68, p<0.01), whereas the indoor PN concentration had some association with outdoor PN values (r = 0.66, p<0.01) even though the indoor PN concentration was occasionally influenced by indoor sources, such as cooking, cleaning and floor polishing activities. Correlation analysis indicated that the outdoor PM2.5 was inversely correlated with the indoor to outdoor PM2.5 ratio (I/O ratio) (r = -0.49, p<0.01), while the indoor PN had a weak correlation with the I/O ratio for PN (r = 0.34, p<0.01). Discussion and Conclusions The results showed that occupancy did not cause any major changes to the modal structure of particle number and size distribution, even though the I/O ratio was different for different size classes. The I/O curves had a maximum value for particles with diameters of 100 – 400 nm under both occupied and unoccupied scenarios, whereas no significant difference in I/O ratio for PM2.5 was observed between occupied and unoccupied conditions. Inspection of the size-resolved I/O ratios in the preschool centre and the classroom suggested that the I/O ratio in the preschool centre was the highest for accumulation mode particles at 600 nm after school hours, whereas the average I/O ratios of both nucleation mode and accumulation mode particles in the classroom were much lower than those of Aitken mode particles. Recommendations and Perspectives The findings obtained in this study are useful for epidemiological studies to estimate the total personal exposure of children, and to develop appropriate control strategies for minimizing the adverse health effects on school children

Whether Adoption Drivers Differ between Click-and-mortar and Pure-play E-payment Services?

How could traditional financial institutions attract online users? Should they mimic their online counter-parts, or compete based on an existing offline business? This research compares different effects of the adoption drivers between pure-play and click-and-mortar e-payment services based on a trust-based Valence Framework. Use intention is proposed to be affected by perceived benefit, perceived risk, and trust, which is in turn affected by familiarity, reputation and security protection. 276 subjects’ responses about Quick Pay (a pure online third-party payment) and Union Pay (an e-payment service offered by a traditional financial institution) were collected. The data analysis reveals: (1) the pure-play e-payment performs much better than the click-and-mortar e-payment except for information risk and property risk; (2) all the path coefficients are significant except the link between perceived risk and use intention for Union Pay; (3) most of the path coefficients for pure-play e-payment service are stronger than those of click-and-mortar e-payment service, except for the links between perceived benefit and intention, trust and perceived risk, and familiarity and trust. These differences can be attributed to different resource endowments owned by service providers. The results suggest that pure-play and click-andmortar e-payment should have different focuses when promoting their services

Distortional Buckling Experiment on Cold-Formed Steel Lipped Channel Columns with Circle Holes under Axial Compression

The objective of this paper is to research the distortional buckling mode and load-carrying capacity of cold-formed thin-walled steel columns with circle holes in web. Compression tests were conducted on 26 intermediate length columns with and without holes. The test members included four different kinds of circle holes. Test results show that the distortional buckling occurred for intermediate columns with holes and the strength of columns with holes was less than that of columns without circle hole. The ultimate strength of columns decreased with the increase of the total transverse width of hole in cross-section of members. For each specimen, a shell finite element Eigen-buckling analysis and nonlinear analysis was also conducted. Analysis results show that the holes can affect on the elastic buckling stress of columns. The shell finite element can be used to model the buckling modes of columns with holes and analyze the load-carrying capacities of members with holes. The comparison on ultimate strength between test results and calculated results using Chinese code GB50018-2002, North American specification AISI S100-2016 and nonlinear Finite Element method was made. The calculated ultimate strength show that results predicted with AISI S100-2016 and analyzed using finite element method are close to test results. The calculated results using Chinese code is higher than test results because Chinese code has no provision to calculate the ultimate strength of members with holes. So the calculated method for cold-formed steel columns with circle holes was proposed. The calculated results using this proposed method show good agreement with test results and can be used in engineering design of cold-formed steel columns with circle hole

Design Method of Bending Load-Carrying Capacity for Sandwich Panels with Different Metal Panel on Both Sides

The sandwich panels, with plain and shallow grain pressed metal plate as the face sheets, and glass wools, rigid polyurethane foam, and rock wools as core materials, have excellent heat insulation and mechanical behavior, and been used as curtain walls for tall buildings in recent years in China. Since wind load and temperature action are the main actions for curtain walls, the sandwich panels are flexural members. In this paper, the design method and design formula of flexural load-carrying capacity and flexural deflection of a kind of sandwich plates with different metal panel on both sides are discussed and proposed. This proposed method considers the different load types, like uniform load, concentrated load, and temperature action, and different core materials. The FE Method can be verified by comparing on shear force distribution coefficients for different sandwich panels with same metal panels on both sides between FE results and calculated results. Then the FE Method can be used to verify the proposed method for shear force distribution coefficients of sandwich plates with different metal panel on both sides. Finally, the proposed method for bending load-carrying capacities for sandwich plates with different metal panel on both sides is verified using FE Method. These verifies show that the proposed method for shear force distribution coefficients and bending load-carrying capacities for sandwich plates with different metal panel on both sides is safe and suitable

Test and Finite Element Analysis on Distortional Buckling of Cold-formed Thin-walled Steel Lipped Channel Columns

High-strength cold-formed thin-walled steel sections have been widely used in the recent several years. However, distortional buckli ng or interaction between it and local buckling can occur for high strength cold-formed thin- walled steel members. This paper desc ribes a series of compression tests performed on lipped channel section columns with V-shape intermediate stiffener in the web and flanges fabricated from cold-formed high strength steel of thickness 0.48 and 0.6mm with nominal yield stress 550MPa. The lipped channel sections were tested to failure with both ends of the columns fixed. The test results of 16 specimens show that the local buckling usually appears before distortional buckling of the specimens and it makes the distortional buckling occur in advance. This interaction of local and distortional buckling may have the effect of reducing the stiffness and bearing capacity of the columns. The comparison on ultimate strength and buckling mode between test results and results of finite element analysis considering geometric and material nonlinear show that finite element method (FEM) can simulate the distortional buckling of cold-formed steel channel columns effectively. The calculative results using Direct Strength Method (DSM) of the North American Specification show that this design method couldn’t consider the reverse effect of interaction between local and distortional buckling on ultimate strength. Direct Strength Method (DSM) considering interaction between local and distortional buckling should be developed

Influence of Gd2O3 and Yb2O3 Co-doping on Phase Stability, Thermo-physical Properties and Sintering of 8YSZ

AbstractThe role of multicomponent rare earth oxides in phase stability, thermo-physical properties and sintering for ZrO2-based thermal barrier coatings (TBCs) materials is investigated. 8YSZ co-doped with 3 mol(Gd2O3 and 3 mol% Yb2O3 (GYb-YSZ) powders are synthesized by solid state reaction for 24 h at various temperatures. As temperature increases, stabilizers are dissolved into zirconia matrix gradually. Synthesized at 1 500 °C, GYb-YSZ is basically composed of cubic phase. GYb-YSZ exhibits excellent phase stability and sinters lower than 8YSZ by nearly three times. The thermal conductivity of GYb-YSZ is much lower than that of 8YSZ, and the thermal expansion coefficient of GYb-YSZ is comparable to that of 8YSZ. The influence of Gd2O3 and Yb2O3 co-doping on phase stability, thermal conductivity and sintering of 8YSZ is discussed