An Investigation into the Correlation of Small Punch and Uniaxial Creep Data for Waspaloy

Within the aerospace sector, the understanding and prediction of creep strains for materials used in high-temperature applications, such as Nickel-based super alloys, is imperative. Small punch testing offers the potential for understanding creep behavior using much less material than conventional uniaxial testing but in contrast to uniaxial creep tests, the stress in small punch creep (SPC) tests is multiaxial. SPC testing can be a valuable tool for validating models of creep deformation, but the key to unlocking its full capability is through the accurate correlation of the creep material properties measured through both techniques. As such, the focus of this paper is to correlate the creep behavior of Waspaloy obtained through conventional uniaxial testing to that obtained via small punch creep testing. Recently, and for low chrome steels, this has been achieved through use of the ksp method, but there are good reasons for believing this technique will not work so well for Nickel-based super alloys. This paper shows this to be the case for Waspaloy and proposes some alternative methods of correlation based on combining the Monkman–Grant relation and the Wilshire equations for both uniaxial and small punch creep. It was found that this latter approach enabled the accurate conversion of SPC minimum displacement rates to equivalent uniaxial minimum creep rates which, when combined with the Wilshire equations, enabled SPC test loads to be converted into equivalent uniaxial stresses (and visa versa) with levels of accuracy that were significantly reduced when compared to using the ksp method. Further, the random error associated with these conversions were dramatically increased.

Effect of Shear Wall Location On Seismic Performance of High Raised Buildings

Multi-storey buildings tend to get damaged mainly during earthquake. Seismic analysis is a tool for the estimation of structural response in the process of designing earthquake resistant structures and/or retrofitting vulnerable existing structures. The principle purpose of this work is to analyze and design a building with a shear wall and also to find the appropriate position of shear wall that result in maximum resistance towards lateral forces and minimum displacement of the structure. In this study, a G+7 multi-storey building of 15 m ×20 m in plan area has been chosen and modelled using ETABS. The developed model was validated by solving manually and the results were validated in ETABS. Thereafter, 4 different new plans were modelled in ETABS located in the same earthquake zone area. These plans have shear wall concepts are implemented on the building at four different locations. Seismic, vibration and response spectrum analysis were performed on these structures. Salient parameters such as storey stiffness, storey displacement and storey drift were computed using the ETABS model. These were compared with that of the frame having no shear walls. By comparing the results obtained at different shear wall locations, the best plan with the shear wall having minimum lateral storey displacement and maximum stiffness is suggested for this location.

Static and Seismic Performance of Buried Pipelines: A review

Today, buried pipes can be considered one of the main substantial infrastructures which has significant role with human life. Such projects serve purposes, including, drain lines, water mains, sewage lines, telephone and electrical conduits, highway and railway culverts, gas and liquid-petroleum lines, coal slurry lines, subway tunnels and various other special functions. This paper focuses on reviewing, describing and understanding the static and dynamic behavior of underground pipes during earthquake events and at rest condition involving seismic vulnerability causes, failure modes of pipelines and loads subjected on pipes. A quick glance on the assisting factors that reduce the pipes breakage due to earthquakes is presented. Also, this paper reviews some previous studies about performance of underground pipes under seismic loads. It was concluded that the soil density has a significant impact on the displacements corresponding to the maximum force. For shallow pipes to obtain the minimum lateral displacement value, it is recommended to use soil density medium to dense state. It was observed also there is a relationship between the spacing of pipes and its displacement so; to obtain the minimum displacement the spacing between the pipes must be at least equal to the pipe diameter.

The Comparison of Three Different Fixation Methods on Bilateral Sagittal Split Ra-mus Osteotomy Mandibular on a 3D of Fully Modelled Mandible by the Finite Ele-ment Method

In this paper, a full mandibular CT-scan in a specific patient is used to model BSSO surgery. The purpose is to compare the three most common fixation methods which are used in BSSO surgery by finite element method. Three different fixations are studied in order to obtain the minimum displacement of the lower jaw and optimum stress and strain on the specified fixation. The methods are two parallel plates with four screws, the operation of triangular screw configuration and one plate with four screws. The plates and the screw are modeled precisely by point clouds of Synthes Brand’s plate and screw. The mechanical properties of the full mandibular and, to obtain a practical model after the surgery, the mean jaw forces are extracted from literatures. It is resulted that the minimum displacement and stresses on the mandible and fixation tools happened in the Triangular screw configuration model and the two other methods have higher stress and lower displacement. Therefore, the mandibular in triangular method, experiences little deformation and the screws tolerates lower stress and strain which is better than the other two methods.

Evaluation of VLBI Observations with Sensitivity and Robustness Analyses

Very Long Baseline Interferometry (VLBI) plays an indispensable role in the realization of global terrestrial and celestial reference frames and in the determination of the full set of the Earth Orientation Parameters (EOP). The main goal of this research is to assess the quality of the VLBI observations based on the sensitivity and robustness criteria. Sensitivity is defined as the minimum displacement value that can be detected in coordinate unknowns. Robustness describes the deformation strength induced by the maximum undetectable errors with the internal reliability analysis. The location of a VLBI station and the total weights of the observations at the station are most important for the sensitivity analysis. Furthermore, the total observation number of a radio source and the quality of the observations are important for the sensitivity levels of the radio sources. According to the robustness analysis of station coordinates, the worst robustness values are caused by atmospheric delay effects with high temporal and spatial variability. During CONT14, it is determined that FORTLEZA, WESTFORD, and TSUKUB32 have robustness values changing between 0.8 and 1.3 mm, which are significantly worse in comparison to the other stations. The radio sources 0506-612, NRAO150, and 3C345 have worse sensitivity levels compared to other radio sources. It can be concluded that the sensitivity and robustness analysis are reliable measures to obtain high accuracy VLBI solutions.

Performance Evaluation of Depth Adjustment and Void Aware Pressure Routing (DA-VAPR) Protocol for Underwater Wireless Sensor Networks

Underwater wireless sensor network (UWSN) has gained its popularity as a powerful technology for monitoring oceans, sea and river. The sensor node drifting along with ocean current offers 4D (space and time) monitoring for real-time underwater application. However, the main challenge arises from the underwater acoustic communication that results in high propagation delay, packet loss and overhead in the network. In order to overcome these issues, a depth adjustment and void aware pressure routing protocol is proposed for UWSN. A greedy forwarding strategy is used to forward the packet. In case a node fails to forward the packet using greedy forwarding strategy, then it immediately switches to the recovery mode. In the recovery mode, the node determines the new depth using particle swarm optimization technique. The global best value gives the new depth with minimum displacement. The void node forwards the packet with minimum displacement without any packet loss and delay.

Effect of Materials and Designs of Brake Rotor Discs on Factor of Safety and Displacement Assessed using Auto Desk Fusion360

Brake rotor is one of the top safety elements in many rotating machines and automobile. The temperature distribution in the rotor, the displacement of the rotor and factor of safety during braking are important parameters which will decide about the safety of vehicle and life of the brake rotor. It is very important to study the influence of materials and design on the factor of safety and displacement for better selection of materials and design of brake rotor discs. In this investigation, three designs of rotor namely a solid disc, a ventilated rotor disc with radial slots and a newly designed rotor consisting aero foil grooves and fins are used which are made of cast iron, titanium alloy and C/C-SiC dual matrices composite material. These discs are modeled in Autodesk Fusion 360. The mechanical behavior such as variation of factor of safety and displacement of the rotor discs are analyzed using Autodesk Fusion360. It is found that titanium alloy seems to provide better distribution of factor of safety in all the three designs of rotor discs. It also gives minimum displacement whereas cast iron rotor gives maximum displacement under the gradually applied static load.

Designing cantilever dimension for low power wireless applications

<span>This paper presents the effect of cantilever width on the displacement pattern for low power acoustic energy propagation. A single layer cantilever configuration is used to design the harvester with Lead Zirconate Titanate (PZT-5H). The device is designed with 10×(1 to 10)×0.62 mm dimension. The displacements of the cantilever are obtained through the simulation analysis. The maximum displacements are found of 9.80E-28 mm with the smallest width while minimum displacement is found from 5 mm width. From the results, it is obvious that, smaller width can result larger displacements, however, rectangular and square cantilever shape can be advantageous for low power applications.</span>