scholarly journals Flexural Creep Effects On Permanent Wood Foundation Made Of Structural Insulated Foam-Timber Panels

Author(s):  
Mahmoud Shaaban Sayed Ahmed

A Permanent Wood Foundation (PWF) is a panel composed of expanded polystyrene insulation and preserved stud cores laminated between oriented-strand boards and preserved plywood. This thesis presents the experimental testing on selected PWFs' sizes to investigate their long-term creep behaviour under sustained soil pressure. The long-term creep tests were performed over eight months, followed by loading the tested panels to destruction to determine their axial compressive strength. The ultimate load test results showed that the structural qualification of PWF is "as good as" the structural capacity of the conventional wood-frame buildings. The obtained experimental ultimate compressive resistance and flexural resistance, along with the developed long-term creep deflection of the wall under lateral soil pressure can be used in the available Canadian Wood Council (CWC) force-moment interaction equation to establish design tables of such wall panels under gravity loading and soil pressure.

2021 ◽  
Author(s):  
Mahmoud Shaaban Sayed Ahmed

A Permanent Wood Foundation (PWF) is a panel composed of expanded polystyrene insulation and preserved stud cores laminated between oriented-strand boards and preserved plywood. This thesis presents the experimental testing on selected PWFs' sizes to investigate their long-term creep behaviour under sustained soil pressure. The long-term creep tests were performed over eight months, followed by loading the tested panels to destruction to determine their axial compressive strength. The ultimate load test results showed that the structural qualification of PWF is "as good as" the structural capacity of the conventional wood-frame buildings. The obtained experimental ultimate compressive resistance and flexural resistance, along with the developed long-term creep deflection of the wall under lateral soil pressure can be used in the available Canadian Wood Council (CWC) force-moment interaction equation to establish design tables of such wall panels under gravity loading and soil pressure.


2021 ◽  
Author(s):  
Mohammad Hossein Zarghooni

A Structural Insulated Panel (SIP) is a panel composed of insulation core laminated between two oriented-strand boards (OSB). SIPs deliver building efficiencies by replacing several components of traditional residental and commercial construction, including: (i) studs; (ii) insulation; (iii) vapour barrier; and (iv) air barrier. A SIP-based structure offers superior insulation, exceptional strength, and fast installation. Besides those benefits, the total construction costs are less with SIPs compared to wood-framed homes, expecially when considering speed of construction, less expensive HVAC equipment required, reduced site waste, reduction construction financing costs, more favourable energy-efficient mortages available, and lower cost of owning a home built with SIPS. This thesis presents the experimental testing on selected SIP sizes to investigate their short- and long-term creep behavior under sustained loading. The experiment study performed in a manner to comply with applicable test methods and, Canadian Codes. Short-term creep test results showed the structural adequacy of the tested panels, while the long-term creep test results established the increase in panel total deflection with time. The ultimate load test results showed that the structural qualification of SIPs is "as good as" the structural capacity of the conventional wood-frame buildings.


2021 ◽  
Author(s):  
Mohammad Hossein Zarghooni

A Structural Insulated Panel (SIP) is a panel composed of insulation core laminated between two oriented-strand boards (OSB). SIPs deliver building efficiencies by replacing several components of traditional residental and commercial construction, including: (i) studs; (ii) insulation; (iii) vapour barrier; and (iv) air barrier. A SIP-based structure offers superior insulation, exceptional strength, and fast installation. Besides those benefits, the total construction costs are less with SIPs compared to wood-framed homes, expecially when considering speed of construction, less expensive HVAC equipment required, reduced site waste, reduction construction financing costs, more favourable energy-efficient mortages available, and lower cost of owning a home built with SIPS. This thesis presents the experimental testing on selected SIP sizes to investigate their short- and long-term creep behavior under sustained loading. The experiment study performed in a manner to comply with applicable test methods and, Canadian Codes. Short-term creep test results showed the structural adequacy of the tested panels, while the long-term creep test results established the increase in panel total deflection with time. The ultimate load test results showed that the structural qualification of SIPs is "as good as" the structural capacity of the conventional wood-frame buildings.


Author(s):  
Muneeb Ejaz ◽  
Norhaida Ab Razak ◽  
Andrew Morris ◽  
Scott Lockyer ◽  
Catrin M. Davies

P91 steels are widely used in high temperature components for power generation. Creep data is often generated through accelerated short term creep tests, for practical reasons, via increasing stress or temperature though this may alter the creep behaviour. Through normalising the creep test stress by tensile strength the Wilshire models reduce the batch to batch scatter in the creep data and enable the prediction of long term creep data from relatively short term test results. In this work it is shown that the Wilshire models fitted to uniaxial creep rupture data can be used to predict failure in both as cast and service exposed multiaxial tests. This is provided that the equivalent stress is the rupture controlling stress, as is the case for the P91 tests examined, and the tensile strength is measured as part of the test programme.


2021 ◽  
Author(s):  
Aleem Shahzad Butt

A series of flexural test and creep tests were conducted on 53 OSB structural insulated sandwich timber panels to predict their behavior when subjected to gravity loading when used in residential and low rise nonresidential buildings. The experiments were designed and performed to test full-scale panels for roof and floor residential construction. The structural adequacy of the developed sandwich panel system is investigated with respect to the effectiveness of the foam core in providing composite action required to meet both strength and serviceability limit-state design reruirements per Canadian Standards for timber design. Strength requirements included flexure and shear, while serviceability check included limiting deflection under operating conditions as well as creep performance under sustained loading. Results from experimental testing were used to draw conclusions with respect the structural qualifications for these SIPs to be "as good as" the structural capacity of conventional wood-frame buildings


2021 ◽  
Author(s):  
Aleem Shahzad Butt

A series of flexural test and creep tests were conducted on 53 OSB structural insulated sandwich timber panels to predict their behavior when subjected to gravity loading when used in residential and low rise nonresidential buildings. The experiments were designed and performed to test full-scale panels for roof and floor residential construction. The structural adequacy of the developed sandwich panel system is investigated with respect to the effectiveness of the foam core in providing composite action required to meet both strength and serviceability limit-state design reruirements per Canadian Standards for timber design. Strength requirements included flexure and shear, while serviceability check included limiting deflection under operating conditions as well as creep performance under sustained loading. Results from experimental testing were used to draw conclusions with respect the structural qualifications for these SIPs to be "as good as" the structural capacity of conventional wood-frame buildings


2021 ◽  
pp. 228947
Author(s):  
Gokhan Gurbuz ◽  
Caglar Bayik ◽  
Saygin Abdikan ◽  
Kurtulus Sedar Gormus ◽  
Senol Hakan Kutoglu

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Seok Jun Kang ◽  
Hoomin Lee ◽  
Jae Boong Choi ◽  
Moon Ki Kim

Ultrasuper critical (USC) thermal plants are now in operation around the globe. Their applications include superheaters and reheaters, which generally require high temperature/pressure conditions. To withstand these harsh conditions, an austenitic heat-resistant HR3C (ASME TP310NbN) steel was developed for metal creep resistance. As the designed life time of a typical thermal plant is 150,000 h, it is very important to predict long-term creep behavior. In this study, a three-state variable continuum damage model (CDM) was modified for better estimation of long-term creep life. Accelerated uniaxial creep tests were performed to determine the material parameters. Also, the rupture type and microstructural precipitation were observed by scanning electron microscopy. The creep life of HR3C steel was predicted using only relatively short-term creep test data and was then successfully verified by comparison with the long-term creep data.


Author(s):  
Kenji Kako ◽  
Susumu Yamada ◽  
Masatsugu Yaguchi ◽  
Yusuke Minami

Type IV damage has been found at several ultra-supercritical (USC) plants that used high-chromium martensitic steels in Japan, and the assessment of the remaining life of the steels is important for electric power companies. The assessment of the remaining life needs long-term creep data for over 10 years, but such data are limited. We have attempted to assess the remaining life by creep tests and by microstructural observation of Grade 91 steels welded pipes which were used in USC plants for over 10 years. Following the results of microstructural observation of USC plant pipes, we find that microstructures, especially distribution of MX precipitates, have large effect on the creep life of Grade 91 steels.


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