Applied Mechanics and Materials Vols. 268-270

Abstract: By the symbolic computation system Maple and the Riccati mapping approach and a variable separation method, some new variable separation solutions ( including solitory wave solutions and periodic wave solutions ) of the (3+1)-dimensional generalized shallow water wave (3DWW) system are derived. Based on the derived solitary wave solution, some novel solitoff solutions are investigated.

Abstract: With the help of the symbolic computation system Maple and the Riccati equation projective approach and a linear variable separation approach, a new family of the variable separation solutions of the (2+1)-dimensional general Ablowitz-Kaup-Newell-Segur(GAKNS) equation is derived. Based on the derived solitary wave solution, we obtain some line-soliton localized excitations.

Abstract: There are three working conditions namely drilling a guide hole, expanding the guide hole and pulling back pipeline in trenchless directional drilling. The position of drill string in the wellbore and loads exerted on the drill string varied in different working conditions. The models of buckling analysis of drill strings under compression, mechanical analysis of drill string under axial compression near drill bit in inclined straight section, mechanical analysis of drill string with multi-centralizers under axial compression near drill bit in inclined straight section, mechanical analysis of drill string near drill bit under axial compression in horizontal section, mechanical analysis of drill string near drill bit under axial tension in horizontal section, mechanical analysis of drill strings near drill bit under axial tension in inclined straight section and mechanical analysis of drill string in failed well are established based on the characteristic of loads and trajectories in each section. The establishment of sectionalized mechanical model of drilling tool is the fundament of further study of force analysis, deformation analysis and stress analysis.

Abstract: The objective of this paper is to use the Noninvasive Strain Measurement System to monitor the pulse pressure of the blood’s undulation in the artery as an index for the clinical diagnosis of arteriosclerosis. In the study, a strain-measuring device (350Ω) is affixed to the left side of the radial styloid process, on the surface of the skin, and is connected to the Strain FleXense. An artery-pressuring tape is set on the left humerus, and the measurement of the wavelength and frequency of the heartbeat is taken to compare with the clinical artery wave. The results show that when the subject is in a comfortable position with moderate physiological levels, the heartbeat has no connection whatsoever with blood pressure. The greatest heartbeat strain, which occurs when the veins and arteries respectively are being cleared, displays as a linear change.

Abstract: Besides the material properties and operating environment, the strain and strain state of the wires in multi-stage twisted rope with large frictional contact force, as applied in traction hoister of suspended access platform, strongly influence their service life. For an accurate quantitative prediction of the performance and a proper understanding of the underlying phenomena, a detailed analysis of the stress-strain distribution along all individual wires is required. For this, a numerical model for a wore rope in traction hoister was describe to be considering the complex strand pattern, mutual interaction by contacts form surrounding strands and contact deformation, in this paper. The model well understood response of wire rope under an axial tensile load and twisting moment, and concise described the effects of rope deformation on the rotate ratio and slip behavior of the hoister. The results of this model were compared with the experiment analyzed, which showed that the inclusion of interfacial forces at the contact locations and their associated effects of internal force of helical wires is importance.

Abstract: Due to complex down-hole conditions and longer drilling time, there are serious casing wear in deep and ultra deep well. It is necessary to carry out a deeper research of the casing wear. Theory of casing wear and prediction method are not perfect in deep well and ultra deep well .The purpose of this paper is to obtain the wear efficiency and friction coefficient which is used to predict wear of the TP140 casing in down hole. A block-ring casing wear tester is specially designed and produced. The wear efficiency and coefficient of friction which is used to predict wear of TP140 casing in different density polysulfide water-based mud is obtained. The influence of the mud density on the TP140 casing wear resistance is analyzed. It is found that the larger mud density, the bigger casing wear efficiency and the friction coefficient.

Abstract: With the development of sour gas reservoir, the utilization of horizontal well technology has a great significance. The accurate prediction of the productivity of horizontal well in developing sour gas reservoir will become more and more important. In this paper, productivity prediction formulas of the horizontal well are established with considering the effect of sulfur deposition on permeability. The effects of the length of horizontal well, the effective thickness of the reservoir, elemental sulfur deposition and reservoir heterogeneity on productivity can be analyzed by established formulas. According to the field case, the calculating results of improved Joshi’s equation approaches the real productivity, which means that it could be used to predict the productivity of horizontal well at initial stage during sour gas reservoir development. The results can be used as a reference for the development of similar sour gas reservoir.

Abstract: Abstract. Structural adhesively bonded and spot welded structures in a car body will experience cyclic loading resulting in degradation, especially in energy absorption performance of welded terms. This paper is focused on the degradation of adhesively bonded and weld-bonded box beams versus equivalent spot welded samples. In the first part of this paper, results from the experimental testing of box beams with different joint methods under cyclic torque are presented. The torsional stiffness of box beams is shown to degrade and box beams with different joint methods show different performance. In the second part, 3-point bending crash test results show the different performance of energy absorption with different joint methods. Bonded and weld-bonded box beams with toughened structural adhesive maintain energy absorption performance compared to the original level, while spot welded profiles show a significant decrease.

Abstract: A new multi-parameter optimal inversion method for jet ratio and jet angle is established by coupling data-driven model theory with variable density anisotropic turbulent buoyant jet model in this paper. In this method, firstly the multi-parameter matching cases of jet ratio and jet angle are computed by the jet model, and the solution space of internal observation site in the computation waters is constructed by numerical simulation results. Secondly, the nonlinear relationship between state variables (dilution degree) and control variables (model multi-parameter) is established by data-driven model theory. Finally the optimal solution is obtained by inputting the needed dilution degree to the relationship. The numerical results show that multi-parameter optimal coupled inversion method is efficient for the optimal jet parameters and has advantages of jet water mixing with environment water.

Abstract: In order to solve the problems of common metallic membrane coupling which is easily damaged a large misalignment compensation coupling is designed. The coupling joins roller coupling with membrane coupling reasonably to ensure the coupling working well in large misalignment condition. Fatigue stress for common coupling and roller-metallic membrane coupling are analyzed by CosmosWorks software. The results show that the zone around bolt holes is easily damaged due to the high stress and lower safety factor. The design of roller-metallic membrane coupling reduces the high stress and lower safety factor zone to increase the anti-fatigue capability of the coupling.