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 : Hamid Lankarani (검색결과 5 건)
- 무료
- 기관 내 무료
- 유료
-
Hamid Khademhosseini Beheshti,Hamid Lankarani 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.5
This paper obtains a Mathematical Dynamic Model (MADYMO) for occupant lumbar load evaluation under CFR Part 23 and 25 at extreme ranges of temperature. The validation of results is performed by full scale sled test results. Aircraft industries are using viscoelastic polyurethane foams as seat cushion. Visco-elastic foams bring not only more comfort to the passengers in long term sitting but it also maintains more safety during unpredicted crashes and hard landings. Aircraft seat cushions are exposed to varying temperature ranges during their life time. This fact has motivated aircraft industries to evaluate the seat cushion dynamic behavior at extreme ranges of temperatures in addition to what is mentioned in Federal Aviation Administration (FAA) Regulations at room temperature. This research provides a methodology based on simulation and modeling to eliminate, or at least, minimize the number of full scale dynamic sled tests defined by regulations for aircraft seats at extreme ranges of temperature.
-
Michael L. McCoy,Rasoul Moradi,Hamid M. Lankarani 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.3
This paper examines the effectiveness of analyzing impact events in mechanical systems for design purposes using simple or low ordered finite elements. Traditional impact dynamics analyses of mechanical systems namely stereomechanics, energy method, stress-wave propagation and contact mechanics approaches are limited to very simplified geometries and provide basic analyses in making predictions and understanding the dominant features of the impact in a mechanical system. In engineering practice, impacted systems present a complexity of geometry, stiffness, mass distributions, contact areas and impact angles that are impossible to analyze and design with the traditional impact dynamics methods. In real cases, the effective tool is the finite element (FE) method. The high-end FEA codes though may be not available for typical engineer/designer. This paper provides information on whether impact events of mechanical systems can be successfully modeled using simple or low-order finite elements. FEA models using simple elements are benchmarked against theoretical impact problems and published experimental impact results. As a case study, an FE model using simple plastic beam elements is further tested to predict stresses and deflections in an experimental structural impact.
-
Sachin Patil,Yi Yang Tay,Farzad Baratzadeh,Hamid Lankarani 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.6
The demand for better structural performance in joining of components for road vehicles prompts the implementation of aluminum alloy friction stir welding technology in the automotive industry. The aim of current study is the creation of a 3-D finite element (FE) friction thermal model and stir welding (FSW) process of dissimilar aluminum alloy and for the estimation of crash worthiness performance of FSW fabricated shock absorber assembly. Thermo mechanical simulations and analysis are performed to understand the thermal behavior in the FSW weld zones. The developed models are correlated against published experimental results in terms of temperature profile of the weld zone. The developed models are then implemented for fabricating vehicle bumper parts to illustrate the performance of FSW welded components during an impact. Customary sled testing for low-speed guard necessities is performed utilizing a grating blend welded test apparatus at Wichita State University (WSU) at the National Institute for Aviation Research (NIAR). A few guard congregations are then appended to the test installation utilizing FSW and conventional Gas bend GMAW welding strategies. Numerical models are likewise created where limited component investigation is utilized to contrast the anticipated harm and the real harm maintained by both of the FSW and GMAW manufactured guards. During the research, a new FSW weld mold is created that allows for a better representation of the desired progressive crack propagation. The FSW fabricated bumper based on the Johnson-Cook failure model yields better failure prediction and is in good agreement to the test. The results from this study provide a guideline for an accurate finite element modeling of a FSW fabricated components and their application in the crashworthiness of such structural components.
-
Sachin Patil,Yi Yang Tay,Farzad Baratzadeh,Hamid Lankarani 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.7
Ever increasing requirements regarding vehicle safety have led to rapid developments in various joining process. Among FSW widely used for Aluminum alloy welded structure of car body because of their remarkable performance in welding. For a better understanding of this performance, it is necessary to determine the behavior of butt weld in service conditions. In earlier phase of this study, thermo mechanical simulations and analysis are performed to understand the thermal behavior in the FSW weld zones. The developed models are correlated against published experimental results in terms of temperature profile of the weld zone. The objectives of the second part of this work is to develop and demonstrate an FE model of bumper and crash box assembly that would improve on the current modeling techniques for the mechanical response of welds in structural problems.
-
The relationship between maternal mental health and communication skills in children in Shiraz, Iran
Najmeh Maharlouei,Hossein Alibeigi,Abbas Rezaianzadeh,Pedram Keshavarz,Hadi Raeisi Shahraki,Hamid Nemati,Kamran B,Lankarani 한국역학회 2019 Epidemiology and Health Vol.41 No.-
OBJECTIVES: Child development is a significant issue in global public health, and maternal mental health (MMH) can have a remarkable effect on children’s development of communication skills. We aimed to investigate the association between MMH and communication skills in a sample of Iranian children. METHODS: This study was conducted in Shiraz, Iran during 2016. In total, 640 mothers who lived in Shiraz and were registered in the Fars Birth Cohort (FBC) study were invited to attend the FBC clinic with their children. A trained physician evaluated MMH using the General Health Questionnaire (GHQ). Additionally, a trained nurse assessed the children’s communication development status using the Ages and Stages Questionnaire for 60-month old children. RESULTS: The majority of the mothers were homemakers (82.8%) and had high school diplomas (38.9%). The mothers’ mean age was 33.7±4.6 years. Seventy-nine (12.3%) children had delayed communication skills, but no significant association was found between children’s communication skills and the mothers’ total GHQ score (p=0.43). In total, 493 mothers (77.0%) had abnormal somatic symptoms, 497 (77.7%) had abnormal anxiety/insomnia, 337 (52.7%) had social dysfunction, and 232 (36.3%) suffered from depression. Logistic regression indicated that after adjusting for confounders, the odds of delayed communication skills were 3-fold higher among the children of mothers with abnormal somatic symptoms than among other children (p=0.01). CONCLUSIONS: The study results confirmed that MMH had a significant impact on children’s communication skills. Moreover, maternal abnormal somatic symptoms exerted the strongest impact on the development of communication skills in 5-year-old children.
KCI
스콜라연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
