Investigation of approximate mode shape and transition velocity of pipe conveying fluid in failure analysis

Structures dynamic characteristics and their responses can change due to variations in system parameters. With modal characteristics of the structures, their dynamic responses can be identified. Mode shape remains vital in dynamic analysis of the structures. It can be utilized in failure analysis, and the dynamic interaction between structures and their supports to circumvent abrupt failure. Conversely, unlike empty pipes, the mode shapes for pipes conveying fluid are tough to obtain due to the intricacy of the eigenvectors. Unfortunately, fluid pipes can be found in practice in various engineering applications. Thus, due to their global functions, their dynamic and failure analyses are necessary for monitoring their reliability to avert catastrophic failures. In this work, three techniques for obtaining approximate mode shapes (AMSs) of composite pipes conveying fluid, their transition velocity and relevance in failure analysis were investigated. Hamilton’s principle was employed to model the pipe and discretized using the wavelet-based finite element method. The complex modal characteristics of the composite pipe conveying fluid were obtained by solving the generalized eigenvalue problem and the mode shapes needed for failure analysis were computed. The proposed methods were validated, applied to failure analysis, and some vital results were presented to highlight their effectiveness.

ZTA Pipes with a Gradient Structure–Effect of the Rheological the Behavior of Ceramic Suspensions on the Gradient Structure and Characterized of the Obtained Products

This paper focuses on the verifying the possibility of producing Al2O3-ZrO2 composite pipes with a gradient structure using centrifugal slip casting method. The aim of the research is to define the correlation between the rheological properties of aqueous suspensions of ceramic powders with different solid loading and obtaining the ZrO2 phase gradient in the Al2O3 matrix. Such products, due to their unique properties, can be utilized in the transport of aggressive substances, even in extreme temperature or corrosive conditions. The suspensions and the sintered samples were characterized by: broad rheological analysis, scanning electron microscopy, X-ray diffraction, stereological analysis and Vickers hardness tests. The study reports on a series of samples produced of ceramic suspensions (70 vol.% Al2O3–30 vol.% ZrO2) differing in the total solid loading in the range of 30–55 vol.%. The results clearly indicate that obtaining the gradient structure of ceramic-ceramic composite pipes is closely related to the rheological properties of the suspensions from which the samples are cast. The phase gradient is obtainable from suspensions 30–40 vol.%, in which the possibility of moving ZrO2 particles relative to the Al2O3 is quite high—these suspensions are characterized by low viscosity and the dominance of viscous over elastic properties (G′ > G″).

Influence Eggshells powder additive on thermal stress of fiberglass/polyester composite tubes

In this study, the influences of eggshell powder application on random fiberglass/polyester composite pipes thermal stresses were investigated experimentally and numerically. The experimental part involved industrializing tube samples which are Egg Shell Powder with Polyester at 50% volume fraction.(E50), Random Fiberglass with plyester at 50% volume fraction (F50) and Egg Shell Powder with Random Fiberglass with Polyester at 50% volume fraction (E25F25). Resin molding procedure and experimental rig design to study how tube samples are faced with thermal loads. Pipes are made with (95 mm) inner diameter, (400 mm) circumference, and (5 mm) wall thicknesses. Computational Fluid Dynamic, ANSYS software package version 11, is simulated with product form SHELL63. Results show that, composite samples (F50) had an average longitudinal strain, while composite samples (E50) had a low longitudinal strain. The composite (F50) had average longitudinal and hoop stress (62.2 MPa, and 61.1 MPa) respectively, while the composite (E50) had low longitudinal hoop stress (28.5 MPa, ad 30.8 MPa) respectively.