The research for partitioned algorithm of coupling of elastic pipe and cross-flow in a cylinder

In the marine flatbed, nuclear power stations and oil fields, the marine risers and heat exchangers are induced vibrations and collision, even caused failure with cross flow. This is a typical problem of bundles vibration in fluid-structure interaction. In this paper, the elastic pipe was separated into several beam elements. And the dynamical equation was adopted to describe the structure. The fluid domain of cylinder was separated into solid elements. And the computational fluid dynamics equation was adopted to describe the fluid. At the fluid-structure coupling interface, the formulas of displacement, velocity and load was derived and the corresponding convergence criterion was also derived. Thus, the partitioned coupling algorithm was established for the elastic pipe and the cross-flow in cylinder. The example showed that, comparing to the results of monolithic coupling algorithm, the error was small. Thus, it proved that the correctness of the partitioned coupling algorithm in this article. And it will provide an effective computational method for vibrations and collision of bundles in a more complex fluid domain

1-(3-Amino-1H-inden-2-yl)ethanone

The title compound, C11H11NO, was synthesized by the reaction of 2-(bromo­meth­yl)benzonitrile and acetyl­acetone in the presence of KOH. In the crystal packing, mol­ecules are linked by inter­molecular N—H⋯O hydrogen bonds into chains running parallel to the b axis. Centrosymmetrically-related chains inter­act further through weak C—H⋯π inter­actions

5-p-Tolyl-1H-tetra­zole

The title compound, C8H8N4, possesses crystallographic mirror symmetry, with four C atoms lying on the reflecting plane, which bis­ects the phenyl and tetra­zole rings. It is composed of a planar r.m.s. deviation (0.0012 Å) tetra­zole ring which is nearly coplanar with the benzene ring, the dihedral angle being 2.67 (9)°. In the crystal, symmetry-related mol­ecules are linked by inter­molecular N—H⋯N hydrogen bonds. The mol­ecules stack along [100] with a π⋯π inter­action involving the phenyl and tetra­zole rings of adjacent mol­ecules [centroid–centroid distance = 3.5639 (15) Å]. The H atom of the N—H group is disordered over two sites of equal occupancy. The methyl H atoms were modelled as disordered over two sets of sites of equal occupancy rotated by 60° with respect to each other

Nonlinear finite element evaluation of the structural response to lateral accelerations of the adobe church of Andahuaylillas, Peru

The Saint Peter Apostle church of Andahuaylillas was built at the early 17th Century and is a representative example of colonial adobe churches in the Andes. Although it has been subjected to constant aesthetic restoration in the recent years, a complete study of its seismic behavior is needed due to the brittle condition of its structural system (composed by a unfired-clay-bricks and earthen mortar known as adobe masonry) and its location in a region with high seismic hazard. This work is part of the integral seismic assessment of the building and focuses on the seismic evaluation of the triumphal arch by means of a static nonlinear analysis. For this purpose, nonlinear finite element (FE) models of the arch were implemented in Abaqus/CAE Explicit and TNO Diana considering a damage-plasticity formulation and a total-strain crack constitutive relationship, respectively, for representing the adobe quasi-brittle behavior. Following an analysis approach simulating up to complete structural collapse, the FE models were used to identify the critical accelerations leading to collapse and the damage patterns. A sensitivity analysis was also carried out considering different material properties for determining the influence of these parameters in the lateral capacity of the studied sub-structure. In addition, different geometrical conditions were considered to increase the capacity of the triumphal arch. Removing the window openings from sidewalls provided more capacity and different crack patterns. Heightening the sidewalls also had a significant influence on capacity

Study on the Application of Biological Tactile in Fast Meat Freshness Detection

The author aimed to explore the application of biological tactile in fast non-destructive meat freshness detection. Used WDW-20 electronic universal testing machine, surveyed chicken, pork and beef the pressure characteristic curves, analysed respectively the relationship between the pressure characteristic curve parameters and the meat freshness. The author also analysed the relationship between the shape of pressure characteristic curve and the meat freshness. The results indicated that in the meal pressure characteristic curve, the curve shape and a number of mechanical parameters could reflect its freshness. Also, different types meat had different structures led them to the different mechanical properties; different types meat characteristic curves, the meat pressure characteristic curve shape and parameters reflected their fresh meat differently. Biological tactile can evaluate meat freshness in a few seconds. This is a promising, economic, simple and practicable way of fast meat freshness detection. Key words: Biological tactile; TVBN; pressure Characteristic curv

The analysis of vortex induced vibration of the flexible pipe in a cylindrical fluid field with cross flow

In view of the vortex-induced vibration of the flexible pipe in the limited fluid domain, the flexible pipe was dispersed into several three-dimensional beam elements and the fluid domain was discretized into solid element in this article. The fluid-structure coupling model and numerical calculation method were set up for flexible pipe in a limited fluid domain. The vortex-induced vibration characteristics were studied for flexible pipe at different positions in the cylindrical fluid domain. The results showed that with the deviation angle which the flexible pipe from inlet velocity increased, the fluid elastic instability was easier to occur and the vibration was more intense for flexible pipe. However, the location was opposite of the inlet velocity, the fluid elastic instability was less likely to occur and the flexible pipe vibration was decreased. Comparing to the vibration results of the test with numerical simulation, the error was small. Therefore, a reliable calculation model and method were presented in this paper