In-situ evaluation of composite structural performance in presence of high stress/strain gradients using multi-axis fiber grating strain sensors

Author(s):  
E. Udd ◽  
K. Black ◽  
W. Schulz ◽  
S. Kreger ◽  
M. Kunzler ◽  
...  
1983 ◽  
Author(s):  
K. Arulanandan ◽  
Y. Dafalias ◽  
L. R. Herrmann ◽  
A. Anandarajah ◽  
N. Meegoda

Author(s):  
Hwajoong Kim ◽  
Ammar Shaqeel ◽  
Solbi Han ◽  
Junseo Kang ◽  
Jieun Yun ◽  
...  

2013 ◽  
Vol 778 ◽  
pp. 919-926 ◽  
Author(s):  
Vlatka Rajčić ◽  
Dean Čizmar ◽  
Mislav Stepinac

Technical Museum is one of the most visited Museums in Zagreb (capital of Croatia). The museum presents scientific and educational centre in the field of technical sciences. The entire structure of the Museum is constructed as a timber structure and as such represents a rare existing example of the European engineering concept of expo-halls timber structures with large span (85m x 40 m) from the early 20 century. In this article overview of different NDTs that were performed in order to assess the structural performance of elements is given; moisture ratio and ultrasound investigations are carried out in situ in order to investigate timber condition. Based on the detected state of the structure reconstruction measures are presented.


Author(s):  
Tobias Orlander ◽  
Katrine Alling Andreassen ◽  
Ida Lykke Fabricius

Abstract Development of high-pressure, high-temperature (HPHT) petroleum reservoirs situated at depths exceeding 5 km and in situ temperature of 170 °C increases the demand for theories and supporting experimental data capable of describing temperature effects on rock stiffness. With the intention of experimentally investigating temperature effects on stiffness properties, we investigated three sandstones from the deep North Sea Basin. As the North Sea Basin is presently undergoing substantial subsidence, we assumed that studied reservoir sandstones have never experienced higher temperature than in situ. We measured ultrasonic velocities in a low- and high-stress regime, and used mass density and stress–strain curves to derive, respectively, dynamic and static elastic moduli. We found that in both regimes, the dry sandstones stiffens with increasing testing temperature and assign expansion of minerals as a controlling mechanism. In the low-stress regime with only partial microcrack closure, we propose closure of microcracks as the stiffening mechanism. In the high-stress regime, we propose that thermal expansion of constituting minerals increases stress in grain contacts when the applied stress is high enough for conversion of thermal strain to thermal stress, thus leading to higher stiffness at in situ temperature. We then applied an extension of Biot’s effective stress equation including a non-isothermal term from thermoelastic theory and explain test results by adding boundary conditions to the equations.


2018 ◽  
Vol 12 (2) ◽  
pp. 180-185 ◽  
Author(s):  
S. M. Li ◽  
T. W. Xu ◽  
Z. X. Jia ◽  
B. C. Zhong ◽  
Y. F. Luo ◽  
...  

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