Examination of the Correlation Between NDE-Detected Manufacturing Abnormalities in MMCs and Ultimate Tensile Strength or Thermomechanical Fatigue Life

Author(s):  
DA Stubbs ◽  
SM Russ ◽  
PT MacLellan
Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 76
Author(s):  
Yanting Gu ◽  
Jilei Zhang

Tensile fatigue performances of selected natural rattan strips (NRSs) and synthetic rattan strips (SRSs) were evaluated by subjecting them to zero-to-maximum constant amplitude cyclic tensile loading. Experimental results indicated that a fatigue life of 25,000 cycles began at the stress level of 50% of rattan material ultimate tensile strength (UTS) value for NRSs evaluated. Rattan core strips’ fatigue life of 100,000 cycles started at the stress level of 30% of its UTS value. Rattan bast strips could start a fatigue life of 100,000 cycles at a stress level below 30% of material UTS value. SRSs didn’t reach the fatigue life of 25,000 cycles until the applied stress level reduced to 40% of material UTS value and reached the fatigue life of 100,000 cycles at the stress level of 40% of material UTS value. It was found that NRSs’ S-N curves (applied nominal stress versus log number of cycles to failure) could be approximated by S=σou(1−H×log10⋅Nf). The constant H values in the equation were 0.10 and 0.08 for bast and core materials, respectively.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Ming-Yuan Shen ◽  
Tung-Yu Chang ◽  
Tsung-Han Hsieh ◽  
Yi-Luen Li ◽  
Chin-Lung Chiang ◽  
...  

Graphene nanoplatelets (GNPs) are novel nanofillers possessing attractive characteristics, including robust compatibility with most polymers, high absolute strength, and cost effectiveness. In this study, GNPs were used to reinforce epoxy composite and epoxy/carbon fiber composite laminates to enhance their mechanical properties. The mechanical properties of GNPs/epoxy nanocomposite, such as ultimate tensile strength and flexure properties, were investigated. The fatigue life of epoxy/carbon fiber composite laminate with GPs-added 0.25 wt% was increased over that of neat laminates at all levels of cyclic stress. Consequently, significant improvement in the mechanical properties of ultimate tensile strength, flexure, and fatigue life was attained for these epoxy resin composites and carbon fiber-reinforced epoxy composite laminates.


2013 ◽  
Vol 800 ◽  
pp. 356-360 ◽  
Author(s):  
Salil Sainis ◽  
Aakarshit Kalra ◽  
G. Dinesh Babu ◽  
M. Nageswara Rao

Cast aluminium alloy 354 has extensive applications in the automobile industry. Due to its attractive combination of mechanical properties and excellent castability, it is being used in production of automobile components like the compressor wheel for turbochargers. Performance of this component under fatigue loading conditions is a critical issue. The present study explores the possibility of improving the fatigue life of the component by bringing in process changes (i) adopting a two-step aging treatment in place of the normally used single step aging treatment (ii) adopting a lower artificial aging temperature (171°C) instead of the temperature normally used for artificial aging (188°C) while performing T61 treatment. In all cases Weibull analysis of fatigue test results was carried out. Weibull analysis of Ultimate Tensile Strength (UTS) values obtained after artificial aging at 171°C and 188°C was also carried out. Among the four variants of two-step aging treatment carried out, the one consisting of 100°C for 5 hours followed by 170°C for 5 hours was found to have the best characteristic fatigue life for the components. The modified T61 treatment where aging was carried out at 171°C instead of the normally used 188°C yielded better characteristic fatigue life as well as better Ultimate Tensile Strength (UTS).


Author(s):  
Haider F. Al-Qrimli ◽  
Mustafa J. Al-Dulaimi ◽  
Kayser A. Ameen

Fibre reinforced polymer composite have been utilised in applications that require high strength-to-weight ratio and durability like automotive and spacecraft components. The literatures has indicated that there is a gap of knowledge in fatigue failure mechanism, and reliable prediction of fatigue life for glass and carbon fibre laminates. This study is to address experimentally the stress level dominated the composite failure mode and how to avoid stress concentration in fatigue design. In addition, it contributes to the scientific knowledge and to further increase the understanding the fatigue behaviour of composite materials structures. To accomplish this investigation goals, three types of materials were fabricated and tested; glass/epoxy, carbon/epoxy, and chopped glass/epoxy. Traditional hand layup technique for composite processing was used to fabricate the composite specimens. It involves manually positioning the reinforcement woven roving in an open mould and pouring, brushing, the resin onto the composites. This study details the experimental results of the ultimate tensile strength and high cycle fatigue, with a stress ratio of 0.1, using ASTM. Results showed that carbon fibre composite had the highest ultimate tensile strength. The power curves conducted from this paper were used to estimate the number of cycles which the material can endure.


2019 ◽  
Vol 13 (4) ◽  
pp. 5804-5817
Author(s):  
Ibrahim Sabry

It is expected that the demand for Metal Matrix Composite (MMCs) will increase in these applications in the aerospace and automotive industries sectors, strengthened AMC has different advantages over monolithic aluminium alloy as it has characteristics between matrix metal and reinforcement particles.  However, adequate joining technique, which is important for structural materials, has not been established for (MMCs) yet. Conventional fusion welding is difficult because of the irregular redistribution or reinforcement particles.  Also, the reaction between reinforcement particles and aluminium matrix as weld defects such as porosity in the fusion zone make fusion welding more difficult. The aim of this work was to show friction stir welding (FSW) feasibility for entering Al 6061/5 to Al 6061/18 wt. % SiCp composites has been produced by using stir casting technique. SiCp is added as reinforcement in to Aluminium alloy (Al 6061) for preparing metal matrix composite. This method is less expensive and very effective. Different rotational speeds,1000 and 1800 rpm and traverse speed 10 mm \ min was examined. Specimen composite plates having thick 10 mm were FS welded successfully. A high-speed steel (HSS) cylindrical instrument with conical pin form was used for FSW. The outcome revealed that the ultimate tensile strength of the welded joint (Al 6061/18 wt. %) was 195 MPa at rotation speed 1800 rpm, the outcome revealed that the ultimate tensile strength of the welded joint (Al 6061/18 wt.%) was 165 MPa at rotation speed 1000 rpm, that was very near to the composite matrix as-cast strength. The research of microstructure showed the reason for increased joint strength and microhardness. The microstructural study showed the reason (4 %) for higher joint strength and microhardness.  due to Significant   of SiCp close to the boundary of the dynamically recrystallized and thermo mechanically affected zone (TMAZ) was observed through rotation speed 1800 rpm. The friction stir welded ultimate tensile strength Decreases as the volume fraction increases of SiCp (18 wt.%).


Alloy Digest ◽  
1997 ◽  
Vol 46 (10) ◽  

Abstract Vasco 9-4-20 (0.20 wt% C) is a premium quality aircraft steel that combines high tensile strength with good fracture toughness. It is a heat-treatable alloy capable of developing an ultimate tensile strength greater than 190 ksi. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as heat treating, machining, and joining. Filing Code: SA-489. Producer or source: Vasco, An Allegheny Teledyne Company.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2171
Author(s):  
Armin Yousefi ◽  
Ahmad Serjouei ◽  
Reza Hedayati ◽  
Mahdi Bodaghi

In the present study, the fatigue behavior and tensile strength of A6061-T4 aluminum alloy, joined by friction stir spot welding (FSSW), are numerically investigated. The 3D finite element model (FEM) is used to analyze the FSSW joint by means of Abaqus software. The tensile strength is determined for FSSW joints with both a probe hole and a refilled probe hole. In order to calculate the fatigue life of FSSW joints, the hysteresis loop is first determined, and then the plastic strain amplitude is calculated. Finally, by using the Coffin-Manson equation, fatigue life is predicted. The results were verified against available experimental data from other literature, and a good agreement was observed between the FEM results and experimental data. The results showed that the joint’s tensile strength without a probe hole (refilled hole) is higher than the joint with a probe hole. Therefore, re-filling the probe hole is an effective method for structures jointed by FSSW subjected to a static load. The fatigue strength of the joint with a re-filled probe hole was nearly the same as the structure with a probe hole at low applied loads. Additionally, at a high applied load, the fatigue strength of joints with a refilled probe hole was slightly lower than the joint with a probe hole.


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