Xueling Fan^1,*, Pin Lu¹, Xiaochao Jin¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.09919

Abstract Ni-based single crystal superalloys have been favored in the high-temperature service zones of aeroengine and gas turbine due to its excellent mechanical properties at high temperature. It is very significant to construct a constitutive model that can accurately capture the mechanical response of Ni-based single crystals for simulation analysis. In this work, a forest dislocation density-based single crystal plasticity constitutive model was developed to capture the mechanical behavior of Ni-based single crystals, including the temperature dependent anomalous yield and tension/compression asymmetry. Firstly, thermally activated cross-slip mechanism was introduced into the hardening model to describe the anomalous yield response. Secondly, the… More >

Zhun Li^1,2,3,*, Zhengrong Ouyang^1,2, Tianbao Sun³, Qiang Li³, Xiaobo Zhao³, Rong Yu³

Energy Engineering, Vol.119, No.4, pp. 1393-1402, 2022, DOI:10.32604/ee.2022.020488

Abstract The building energy consumption is an important part among the total society energy consumption, in which the energy consumption for air conditioning occupies almost 70%. The energy consumption of the air conditioning system for fresh air handling can be saved effectively when the exhaust air energy could be recovered to preheat or precool the fresh air. Considering the install locations requirements on field, the pump-driven heat pipes (PHP) were developed as heat recovery ventilators (HRVs) and used in an existing experiment building in Beijing Urban. The thermal performance of the PHP HRVs was tested in real operation time periods under… More >

Tareq Al-hababi^1,2, Nizar Faisal Alkayem^1,3, Li Cui⁴, Shixiang Zhang⁵, Cong Liu⁶, Maosen Cao^1,2,*

Structural Durability & Health Monitoring, Vol.16, No.1, pp. 15-35, 2022, DOI:10.32604/sdhm.2022.020418

Abstract A significant amount of research is concerned with dynamic modal parameters for damage detection of structural conditions due to their simplicity in use and feasibility. However, their use for damage detection should be performed with special attention, particularly in operational and environmental conditions subjected to temperature changes. Beams in construction industries experience different loading types, such as temperature changes leading to crack initiation and propagation. Changed physical and dynamic properties such as natural frequencies and mode shapes indicate that damage has occurred within the structures. In this study, vibration analysis of cantilever and cantilever simply supported beams has been carried… More >

Dongyue Gao¹, Yunlong Ma², Zhanjun Wu^3,*, Yuebin Zheng³, Hongbo Lu¹

Structural Durability & Health Monitoring, Vol.15, No.1, pp. 23-37, 2021, DOI:10.32604/sdhm.2021.013737

Abstract Guided waves based damage detection methods using base signals offer the advantages of simplicity of signal generation and reception, sensitivity to damage, and large area coverage; however, applications of the technology are limited by the sensitivity to environmental temperature variations. In this paper, a Spearman Damage Index-based damage diagnosis method for structural health condition monitoring under varying temperatures is presented. First, a PZT sensor-based Guided wave propagation model is proposed and employed to analyze the temperature effect. The result of the analysis shows the wave speed of the Guided wave signal has higher temperature sensitivity than the signal fluctuation features.… More >

Serrano-Bernardo F¹, JL Rosúa¹, M Díaz-Miguel²

Phyton-International Journal of Experimental Botany, Vol.76, pp. 27-38, 2007, DOI:10.32604/phyton.2007.76.027

Abstract The Mediterranean region is considered one of the most important zones worldwide in terms of plant diversity. Sierra Nevada (S Spain) is a unique mountain massif within the high-mountain systems of the Mediterranean. It is of great floristic importance and very rich in endemic species. However, it requires numerous tasks for restoring plant cover due to the constant anthropic degradation, especially because of the ski station located near the second-highest peak of the mountain. One of the restoration efforts consists of trying to reproduce, in the laboratory, the ideal conditions to pre-germinate seeds of some of the species most threatened… More >

N.H.M. Kamrujjaman Serker¹, Zhishen Wu

Structural Durability & Health Monitoring, Vol.5, No.2, pp. 87-108, 2009, DOI:10.3970/sdhm.2009.005.087

Abstract This paper presents the study on the temperature sensitivity of some vibration-based damage identification techniques. With the help of a simple supported beam with different damage levels, reliability of these techniques for damage identification in a changing environmental temperature condition was investigated. The temperature effect was considered as the change in modulus of elasticity of the material. The techniques evaluated herein are based on measured modal parameters which use only few mode shapes and/or modal frequencies of the structure that can easily be obtained by dynamic tests. The effect of temperature on identification of different level of damages at different… More >

Yugai Huang^1,2,3, Yu Shang^1,4, Wenqing Li¹, Jiajing He¹, Hairong Zhou¹, Bin Gu^1,*

CMC-Computers, Materials & Continua, Vol.61, No.2, pp. 701-710, 2019, DOI:10.32604/cmc.2019.03109

Abstract The configurations of molecular clusters have significant impacts on their growth into fine particles in atmosphere. In this paper, we explore the topology space of the structure of H2SO4·NH3 dimer with a novel sampling technique of meta-dynamics (MTD) method and ab initio molecular dynamics simulations. The simulations are carried out at the temperatures of both 50 K and 242 K, which represent the typical high and low latitudes of troposphere. The results show that, compared with only traditional MD simulations, the structure samplings are significantly accelerated with MTD method. Therefore, more isomers of the dimer are discovered within the same… More >

Cao Guohua¹, Zhu Zhencai¹, Peng Weihong², Wang Jinjie¹, Liu Zhi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.94, No.2, pp. 119-138, 2013, DOI:10.3970/cmes.2013.094.119

Abstract The single helical structure is twisted by surrounding helical units with clearance or not between two layers. In order to master the thermal expansion behavior, the theory has been developed for the analysis of these helical structures. The previously deduced linear expressions of thermal expansion coefficients for the gapless structure model (GM) is used and the analytical method is applied to the clearance structure model (CM) and clearance-gapless structure model(CGM) under two boundary conditions. For further evaluating the analytical expressions of two models, the finite element models of the single helical structure surrounding by helical units with lang lay and… More >

Cao Guohua, Li Kai, Zhu Zhencai, Peng Weihong, Mao Xianbiao

CMES-Computer Modeling in Engineering & Sciences, Vol.83, No.4, pp. 403-424, 2012, DOI:10.3970/cmes.2012.083.403

Abstract In order to master the geometric and mechanical behavior of helical structure under complicated condition such as the hoisting rope in mine shaft and the transmitting cable in electric power, the thermal expansion characteristic of single helical structure is systematically investigated under temperature effect in different layer. Linearly explicit expressions of axial strain and increment of helical angle for the helical unit of the ith layer are developed. Based on theory of curve by Love and theory of wire rope by Costello, the linearly explicit expressions of tension, torsion and bending moment of the helical unit are presented. After that,… More >