Current Issue : January - March Volume : 2016 Issue Number : 1 Articles : 5 Articles
The posterior density of structural parameters conditioned by the measurement is obtained by a differential evolution adaptive\nMetropolis algorithm (DREAM). The surface of the formal log-likelihood measure is studied considering the uncertainty of\nmeasurement error to illustrate the problem of equifinality. To overcome the problem of equifinality, the first two derivatives of\nthe log-likelihood measure are proposed to formulate a new informal likelihood measure for the sake of improving the accuracy of\nthe estimator.Moreover, the proposed measure also reduces the standard deviation (uncertain range) of the posterior samples.The\nbenefit of the proposed approach is demonstrated by simulations on identifying the structural parameters with limit output data\nand noise polluted measurements....
As an important parameter in blasting design, charging structure directly influences blasting effect. Due to complex conditions\nof this blasting and excavating engineering in Jiangsu, China, the authors carried out comparative researches with coupling\nstructure, air-decoupling structure, and water-decoupling structure. After collecting, comparing, and analyzing produced signals\non blasting vibration, the authors summarized that when proportional distances are the same, water-decoupling structure can\nreduce instantaneous energy of blasting vibration more effectively with more average rock fragmentation and less harm of dust.\nFrom the perspective of impedance matching, the present paper analyzed influence of charging structure on blasting vibration\nenergy, demonstrating that impedance matching relationship between explosive and rock changes because of different charging\nstructures. Through deducing relationship equation that meets the impedance matching of explosive and rock under different\ncharging structures, the research concludes that when blasting rocks with high impedance, explosive with high impedance can\nbetter transmits blasting energy. Besides, when employing decoupling charging, there exists a reasonable decoupling coefficient\nhelping realize impedance matching of explosive and rock....
Metal foam cladding emerges as a promising measure for structure protection against close range blast. With proper cladding\ndesign, a considerable amount of energy can be absorbed while the load transmitted to the protected structure can be lowered to a\ncontrollable level, leading to less damage of the protected structure. However, it is not clear whether the in-structure shock can be\nmitigated by attaching foam cladding. The present study theoretically investigates the response of a structural member subjected to\na close range blast, for both scenarios with and without attaching foam cladding. Subsequently, shock response spectra are employed\nto assess the in-structure shock of both situations. It is found that applying foam cladding does not effectively mitigate in-structure\nshock of surface structures....
In the past few decades, high-rise buildings have received a renewed interest in many city business locations, where land is scarce,\nas per their economics, sustainability, and other benefits. Taller and taller towers are being built everywhere in the world. However,\nthe increased frequency of multi hazard disasters makes it challenging to balance between a resilient and sustainable construction.\nAccordingly, it is essential to understand the behavior of such structures under multi hazard loadings, in order to apply such\nknowledge to design. The results obtained from the dynamic analysis of two different high-rise buildings (54-story and 76-story\nbuildings) investigated in the current study indicate that earthquake loads excite higher modes that produce lower interstory drift,\ncompared to wind loads, but higher accelerations that occur for a shorter time. Wind-induced accelerations may have comfort\nand serviceability concerns, while excessive interstory drifts can cause security issues. The results also show that high-rise and\nslender buildings designed for wind may be safe under moderate earthquake loads, regarding the main force resisting system.\nNevertheless, nonstructural components may present a significant percentage of loss exposure of buildings to earthquakes due to\nhigher floor acceleration. Consequently, appropriate damping/control techniques for tall buildings are recommended for mitigation\nunder multihazard...
According to the kinematic equation of the die-cutting machine with the dual-elbow-bar mechanism, the angular acceleration curve\nfigure can be obtained exactly through the analysis of MATLAB program when the die-cutting machine runs at the highest speed\n(6000 r/h).The material properties of the cam driving mechanism are analyzed by QFD (Quality Function Deployment) method,\nand the optimum design project is presented based on conjugate cam driving mechanism. The reverse design and the outline of\nconjugate cam mechanism are obtained by MATLAB program. The kinematical form of optimized design conjugate cam driving\nmechanism is simulated and analyzed by ADAMS software. The results show that the optimum design mechanism could raise the\nhighest speed of the die-cutting machine up to 7500 r/h and improve the overall performance of the machine....
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