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 : Mahdi Ahmadpour (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
-
Failure analysis of unidirectional polymeric matrix composites with two serial pin loaded-holes
Mohammad Mahdi Attar,Farzan Barati,Mahdi Ahmadpour,Ehsan Rezapour 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.6
The objective of this study is to investigate the effects of geometrical and physical parameters on failure modes and failure loads in unidirectional polymeric matrix composites with two serial pin loaded holes, analytically and experimentally. It is assumed that all of unidirectional fibers in the laminate lie in one direction while loaded by a load p 0 at infinity, parallel to the direction of the fibers. To derive equilibrium equations based on a Shear-Lag theory, a rectangular arrangement of fibers is considered and with the proper use of boundary and boundness conditions, stress and displacement fields are computed within the laminate, along with the surrounding pinholes. Finally by using the Hashin criterion failure modes and failure loads are estimated. To validate analytical results based on shear-lag theory, an experimental program is carried out. A very good agreement is observed between two procedures. Based on results, in small sizes of two pins, the dominant failure mode is bearing and with the increasing of hole sizes, failure modes are changed to tension and shear modes.
-
Effects of fresh mineralized dentin and cementum on socket healing: a preliminary study in dogs
Mahdi Kadkhodazadeh,Majid Ghasemianpour,Negar Soltanian,Gholam Reza Sultanian,Shahriar Ahmadpour,Reza Amid 대한구강악안면외과학회 2015 대한구강악안면외과학회지 Vol.41 No.3
Objectives: Dentin is composed of many minerals and growth factors. Based on this composition, we studied its effect as a possible regenerative material for alveolar healing. Materials and Methods: This study was conducted using four 2.5-year-old mongrel dogs (male; weight, 25 to 30 kg). The third mandibular premolars were carefully mobilized with a dental elevator and then removed using forceps. The crown portions of the extracted teeth were removed with cutters, and the root portions of the remaining teeth were collectively trimmed as closely as possible to 350 to 500 μm. Dentin and cementum (DC) chips harvested from the extracted teeth were soaked in blood and packed into the fresh sockets (autograft). Biopsies were performed at the ends of day 14 and day 56 following implantation. Data were expressed as mean±standard deviation and compared with t-test results. Results: The ratio of S A (bone) to total area of each probe was determined and was 170±16 μm 2 for the control group and 71±14 μm 2 for the DC group, a significant difference (P<0.05). Conclusion: DC particulate grafts offered no improvement in bone regeneration in alveolar extraction sockets.
-
The effect of Al2O3 nano additions on failure of GFRP plate with two parallel pin loaded holes
Mohammadmahdi Attar,S. Mahdi Ahmadpour,S. Shahin Banisadr,Arash Mohammadi,S. Zahra Mirmoradi,Zohreh Shirazi 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.6
The aim of this study is to scrutinize the effect of nano-additions on failure modes and loads of glass-epoxy laminate subjected two parallel pin-loaded holes, experimentally and numerically. Furthermore, the effect of physical and geometrical parameters such as the ratio of free edge distance of laminated composite to holes diameter (e/d) and the ratio of centre to centre distances of holes to holes diameter (M/d) have been investigated. Afterwards, to exactly prognosticate failure modes and the ultimate load obtained from the experimental procedure, a numerical simulation in finite element software was implemented. There have found a close agreement between two methods. It should be acknowledged that after augmenting glass-epoxy laminate with nano-addition Al 2 O 3 , there was seen to be a clear difference between the two samples while the bearing strength of reinforced samples has been improved.
-
Compressive quasistatic and dynamic behavior of SiC/ZrO2 aluminum-based nanocomposite
Jamshid Nemati,Meysam Toosian,Seyed Shahin Banisdar,Seyed Mahdi Ahmadpour 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.8
This research investigated the mechanical properties of aluminum-based nanocomposite. The spark plasma sintering method was adopted to fabricate the samples. The nanoparticles and the base metal powder were mechanically mixed in four volumetric ratios under an argon-gas-neutral atmosphere using a planetary ball milling machine. The dynamic and static compressive behaviors of the samples were studied under three different loading rates, and the microhardness of the specimens was measured. Results revealed significant improvements in microhardness, quasistatic, and the dynamic compressive strength, which can be attributed to several mechanisms, including the load transfer effect, Hall-Patch strengthening, Orowan strengthening, coefficient of thermal expansion, and elastic modulus mismatch effects. The most effective mixture was found to be 92 vol% of Al, 4 vol% of SiC, and 4 vol% of ZrO 2 . This combination of raw materials led to ultimate strengths of 204.517, 396.825, and 572.624 MPa at strain rates of 0.33, 13.33, and 2000 s -1 , respectively.
ScienceON
스콜라연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
