http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Borujerdi, J. (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Application of numerical models to determine wind uplift ratings of roofs
Baskaran, A.,Borujerdi, J. Techno-Press 2001 Wind and Structures, An International Journal (WAS Vol.4 No.3
Wind uplift rating of roofing systems is based on standardised test methods. Roof specimens are placed in an apparatus with specified table size (length and width) then subjected to the required wind load cycle. Currently, there is no consensus on the table size to be used by these testing protocols in spite of the fact that a table size plays a significant role in evaluating the performance. This paper presents a study with the objective to investigate the impact of table size on the performance of roofing systems. To achieve this purpose, extensive numerical experiments using the finite element method have been conducted to investigate the performance of roofing systems subjected to wind uplift pressures. Numerical results were compared with results obtained from experimental work to benchmark the numerical modeling. Required table size and curves for the determinations of appropriate correction factors are suggested. This has been completed for various test configurations with thermoplastic waterproofing membranes. Development of correction factors for assemblies with thermoset and modified bituminous membranes are in progress. Generalization of the correction factors and its usage for wind uplift rating of roofs will be the focus of a future paper.
-
Numerical solution of non-Fourier heat transfer during laser irradiation on tooth layers
S. Falahatkar,A. Nouri-Borujerdi,M. Najafi,A. Mohammadzadeh 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.12
This study reports on the simulation of temperature distribution of human tooth under a laser beam based on non-Fourier models. The temperature in the tooth depth that directly results from the conduction heat transfer process is caused by the lengthy thermal relaxation time in the tooth layers. A detailed tooth composed of enamel, dentin, and pulp with unstructured shape, uneven boundaries, and realistic thicknesses was considered. A finite difference scheme was separately adopted to solve time-dependent equations in solid layers and soft tissue of the tooth. In this study, a dual-phase-lag non-Fourier heat conduction model was applied to evaluate temperature distribution induced by laser irradiation. Results show that for the laser-irradiated tooth, the phase lag time of heat flux (τ q ) greatly affects the temperature of the early stage, whereas the phase lag time of the temperature gradient (τ T ) significantly influences the temperature of the later stage. Prediction of temperature profile in the tooth based on this investigation is more real using the non-Fourier model (i.e., τ q = 16 and τ T = 2 millisecond) compared with experimental studies. Meanwhile, the Fourier model (τ q = τ T ) or classical Fourier form (τ q = τ T = 0) and the thermal wave model (τ q = 16 and τ T = 0) led to unreal heated point on the enamel. The effects of laser parameters, such as laser exposure time and laser intensity on the pulp, were also investigated. Increasing the laser duration and simulation time after laser irradiation was a logical approach to pulp ablation compared with increasing the laser intensity.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
