Development of Test Equipment for Measuring Compression Characteristics of Sheet Gaskets at Elevated Temperature

2007 ◽  
Author(s):  
Toshimichi Fukuoka ◽  
Masataka Nomura ◽  
Yoshihiko Hata ◽  
Takashi Nishikawa
Keyword(s):  
Elevated Temperature ◽  
Compression Test ◽  
Elevated Temperatures ◽  
Testing Procedure ◽  
Great Difficulty ◽  
Test Equipment ◽  
Experimental Point ◽  
Stress Strain ◽  
Sealing Performance ◽  
Compression Characteristics

Evaluation of the sealing performance of pipe flange connection is significantly important for the safety of pipe line structures. The compression characteristics of sheet gaskets primarily affect the mechanical behavior of flanged connections. It is known that the stiffness of sheet gaskets decreases with an increase in temperature. Therefore, the compression test must be conducted at various levels of elevated temperatures. From the experimental point of view, however, a great difficulty is involved in measuring the compression characteristics of gaskets at elevated temperature. For this reason, a definite testing procedure has not yet been established. In this paper, a prototype of compression test equipment has been developed for measuring the stress-strain curves of sheet gaskets at elevated temperature. The test equipment is compact and the experiments can be conducted with a fairly easy operation. It can control the gasket stress from zero to 30MPa while keeping the temperature of test specimen at different levels from room temperature to 300° C and higher. Aramid sheet gaskets are selected as test specimens. Experimental results show that the gasket stiffness drops with an increase in temperature. The shapes of the compression curves at different temperatures are similar, and those curves move in the direction of lower stiffness as the temperature is increased. It is concluded that the test equipment proposed here has a high promise to measure the stress-strain curves of sheet gaskets and estimate the sealing performance of pipe flange connections at elevated temperature.

Evaluation of Sealing Behavior of Gaskets at Elevated Temperature Based on the Test Method HPIS Z105 Proposed in Japan

2009 ◽  
Author(s):  
Hirokazu Tsuji ◽  
Takashi Honda ◽  
Atsushi Yamaguchi ◽  
Takashi Kobayashi ◽  
Toshiyuki Sawa
Keyword(s):  
Elevated Temperature ◽  
Temperature Stress ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Testing Procedure ◽  
Test Method ◽  
Post Exposure ◽  
Sealing Performance ◽  
Stress Cycling ◽  
Spiral Wound

A method to test the sealing performance of gaskets at elevated-temperatures, HPIS Z105, will be published soon in Japan. This paper discusses the gasket testing procedure to obtain the sealing behavior of gasket at elevated-temperatures. This testing procedure extends the room-temperature gasket testing procedure HPIS Z104 to the elevated-temperatures. The purpose of this testing procedure is to evaluate the effect of a moderate exposure at the elevated-temperature on the sealing performance of the non-asbestos gasket. This testing procedure consists of 4 parts; pre-exposure room-temperature tightness test, aging exposure of gasket at elevated-temperature, stress cycling disturbances, and post-exposure room-temperature tightness test. In order to demonstrate the validity of the testing procedure, measurements of leak rates of several types of sheet gaskets and spiral wound gaskets are carried out. It has shown that the sealing behavior can be well characterized using the proposed testing procedure.

Polycrystal Simulations Investigating the Effect of Additional Slip System Availability in a 6063 Aluminum Alloy at Elevated Temperature

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Antoinette M. Maniatty ◽  
David J. Littlewood ◽  
Jing Lu
Keyword(s):  
Aluminum Alloy ◽  
Elevated Temperature ◽  
Compression Test ◽  
Elevated Temperatures ◽  
Material Model ◽  
Grain Structure ◽  
Slip Systems ◽  
Modeling Framework ◽  
Element Analysis ◽  
6063 Aluminum Alloy

In order to better understand and predict the intragrain heterogeneous deformation in a 6063 aluminum alloy deformed at an elevated temperature, when additional slip systems beyond the usual octahedral slip systems are active, a modeling framework for analyzing representative polycrystals under these conditions is presented. A model polycrystal that has a similar microstructure to that observed in the material under consideration is modeled with a finite element analysis. A large number of elements per grain (more than 1000) are used to capture well the intragranular heterogeneous response. The polycrystal model is analyzed with three different sets of initial orientations. A compression test is used to calibrate the material model, and a macroscale simulation of the compression test is used to define the deformation history applied to the model polycrystal. In order to reduce boundary condition effects, periodic boundary conditions are applied to the model polycrystal. To investigate the effect of additional slip systems expected to be active at elevated temperatures, the results considering only the 12 {111}⟨110⟩ slip systems are compared to the results with the additional 12 {110}⟨110⟩ and {001}⟨110⟩ slip systems available (i.e., 24 available slip systems). The resulting predicted grain structure and texture are compared to the experimentally observed grain structure and texture in the 6063 aluminum alloy compression sample as well as to the available data in the literature, and the intragranular misorientations are studied.

scholarly journals Effect of Geopolymer Concrete Encased I-Section and Geopolymer CFST Column Under Fire

2021 ◽  
Vol 10 (10) ◽  
pp. 51-58
Author(s):  
Md Mustafeezul Haque* ◽  
◽  
Dr. Sabih Ahmad ◽  
Abdul Hai ◽  
Md Marghoobul Haque ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Elevated Temperatures ◽  
Concrete Column ◽  
Geopolymer Concrete ◽  
Strength Parameters ◽  
Stress Strain ◽  
Conventional Concrete ◽  
Composite Column ◽  
Fire Disaster

Geopolymer concrete can resist fire quite well when compared with conventional concrete. Recent studies to observe the behaviour of geopolymer composite column under the effect of fire are very few. In this paper results in terms of stress, strain and deformation of geopolymer composite column expressed to elevated temperature are presented. It was observed that geopolymer composite column performs better at elevated temperatures than the conventional composite column. This tests are performed with four composite column with geopolymer concrete and conventional concrete which is tested at four elevated temperatures i.e., 400 oC, 500 oC, 600 oC, 700 oC and 800 oC to evaluate the strength parameters. It results geopolymer concrete column can be used where fire disaster chances are high.

Effect of Aging Time on Sealing Performance of Non-Asbestos Gasket at Elevated Temperature

2004 ◽  
Author(s):  
Hirokazu Tsuji ◽  
Hirokazu Kitagawa ◽  
Noriyoshi Kodaira
Keyword(s):  
Elevated Temperature ◽  
Aging Time ◽  
Temperature Fluctuation ◽  
Stress Strain ◽  
Mixed Condition ◽  
Testing Apparatus ◽  
Sealing Performance ◽  
Conventional Tests ◽  
The Difference ◽  
Spiral Wound

Tests were concluded by a testing apparatus for ROTT/HOTT, which could continuously control the gasket temperature up to 450°C, under either the stress controlled condition or the strain controlled condition, while the conventional tests were conducted under the stress/strain mixed condition with the temperature fluctuation. The sealing performance of asbestos and non-asbestos gaskets was examined. For the non-asbestos SWG (Spiral wound gaskets) tested by the HOTT, the values of Tp at temperature 210°C and 300°C are distributed over 103∼104, while the value of Tp at 420°C is shifted to the relatively lower level of 102∼103. The non-asbestos SWG has same sealing performance as the substitute for the asbestos SWG between 210°C∼420°C. The PHOTT (Preheated Hot Operational Tightness Test, proposed in this study) is also carried out to compare the evaluation of sealing performance at 300°C with that at 210°C. The difference of sealing performance between the HOTT and the PHOTT at 300°C appears. The PHOTT is unavailable as a simplified substitutive test for the HOTT.

Sealing Performance Evaluation of Pipe Flange Connection Under Elevated Temperatures

2007 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Yoshio Takagi ◽  
Hiroyasu Torii
Keyword(s):  
Elevated Temperature ◽  
Stress Distribution ◽  
Internal Pressure ◽  
Elevated Temperatures ◽  
Flange Connection ◽  
Gas Leakage ◽  
Sealing Performance ◽  
Nominal Size ◽  
Operational Temperature ◽  
Contact Stress Distribution

Since a lot of pipe flange connections are exposed to elevated temperature during operation, it is important to evaluate the sealing performance of the connections under operational temperature. In this study, the sealing performance of pipe flange connection was experimentally evaluated by measuring the amount of gas leakage at room temperature (RT), 100 °C and 200 °C in addition to internal pressure. Non-asbestos graphite gaskets were used in the experiment. The nominal size of the pipe flange used during the experimental study was 3 inch. The eight bolts and nuts were tightened according to ASME PCC-1 and the Japanese method (HPIS). During assembly, the axial bolt force was individually measured with strain gauges attached to each bolt. The scatter in the axial bolt force during the assembling process was examined and compared between the ASME and the HPIS. In addition, the gasket contact stress distribution of each assembly process was calculated by finite element method under elevated temperature and internal pressure. In the FE study, experimentally measured physical properties such as elastic modulus and thermal expansion were used. ηhe amount of leakage was estimated from the contact gasket stress distribution obtained by FE analysis. The estimated axial bolt forces were compared with those of experimental ones.

Temperature Dependent Plastic Deformation Behavior of AZ31 Magnesium Alloy in Uniaxial and Biaxial Compressions

2016 ◽  
Vol 725 ◽  
pp. 421-426 ◽  
Author(s):  
Ichiro Shimizu
Keyword(s):  
Elevated Temperature ◽  
Flow Stress ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Deformation Behavior ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Temperature Dependency ◽  
Stress Strain ◽  
Stress Strain Relation

Metal forming of magnesium alloys often performed at elevated temperature, because magnesium alloys exhibit peculiar stress-strain relation and inferior ductility compared to conventional metals at room temperature. In the present study, deformation behavior and formability of cast and extruded AZ31 magnesium alloys under uniaxial and biaxial compressions at room temperature and at elevated temperatures were investigated. The results revealed that the compressive stress-strain relation of AZ31 magnesium alloy changed not only with the initial texture but also with the deformation temperature. The temperature dependency of flow stress of the cast alloy was smaller than that of the extruded alloy probably because of less influence of pre-deformation. In addition, the influence of compressive deformation pattern upon flow stress of the extruded alloy remained even at elevated temperature to 523 K. The temperature dependency of compressive fracture was also discussed and it was found that the equi-biaxial condition improved the compressive formability at elevated temperatures.

Durability and Damage Development in Woven Ceramic Matrix Composites Under Tensile and Fatigue Loading at Room and Elevated Temperatures

1999 ◽  
Author(s):  
Anwarul Haque ◽  
Md. M. Rahman ◽  
Hisham T. Mohamed ◽  
Hassan Mahfuz ◽  
Uday K. Vaidya ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Cyclic Loading ◽  
Elevated Temperatures ◽  
Failure Strain ◽  
Ceramic Matrix Composites ◽  
Matrix Cracking ◽  
Woven Composites ◽  
Damage Development ◽  
Stress Strain ◽  
Damage Initiation

Abstract This paper investigates the damage development in SiC/SiNC woven composites under tensile and cyclic loading both at room and elevated temperatures. The ultimate strength, failure strain, proportional limit and modulus data at a temperature range of 23°C–1380°C are generated. The tensile strength and the modulus of SiC/SiNC woven composites have been observed to decrease insignificantly with increased temperatures beyond the linear portion of the stress/strain plot. The stress/strain plot shows a pseudo-yield point at 25% of the failure strain (εf) which indicates damage initiation in the form of matrix cracking. The evolution of damage beyond 0.25 εf both at room and elevated temperature comprises of multiple matrix cracking, interfacial debonding and fiber pullout. Although the nature of the stress/strain plot shows damage-tolerant behavior under static loading both at room and elevated temperature, the life expectancy of SiC/SiNC composites degrades significantly under cyclic loading at elevated temperature. This is mostly due to the interactions of fatigue damage caused by the mechanically induced plastic strain and the damage developed by the creep strain. The in situ damage evolutions are monitored by acoustic event parameters, ultrasonic C-scan and stiffness degradation.

scholarly journals Residual stress-strain relationship for the biochar-based mortar after exposure to elevated temperature

2021 ◽  
pp. e00540
Author(s):  
Satheeskumar Navaratnam ◽  
Hendrik Wijaya ◽  
Pathmanathan Rajeev ◽  
Priyan Mendis ◽  
Kate Nguyen
Keyword(s):  
Residual Stress ◽  
Elevated Temperature ◽  
Stress Strain ◽  
Strain Relationship
Sign in / Sign up

Export Citation Format

Share Document