基于ANSYS的金属软管的瞬态动力学分析

运用非线性有限元法,采用三维壳单元Shell93和空间梁单元Beam189,利用耦合和约束理论,在ANSYS中建立金属软管的有限元模型,对金属软管进行瞬态动力学有限元分析,得到金属软管在一个周期内的阻尼迴滞曲线以及动态响应,并将计算结果与试验结果进行比较,证明了有限元建模及其计算结果的正确性,为金属软管的力学性能和动态设计分析以及将来的寿命分析的研究提供了参考.     

金属软管的非线性有限元分析

采用三维壳单元shell93和空间梁单元beam89，运用耦合和约束方程理论，利用ANSYS的参数化设计语言(APDL)对金属软管进行了参数化的三维实体建模。对金属软管的力学特性进行了分析计算，并将计算结果与实验数据相对照，确定了有限元方法的可靠性。根据分析结果，对金属软管的特性进行了总结，结论对金属软管的设计和应用具有重要参考价值。     

基于ANSYS的金属软管的动态有限元分析

运用非线性有限元法,采用三维壳单元Shell93和空间梁单元Beam18,利用耦合和约束理论,在ANSYS中建立金属软管的有限元模型,对金属软管进行动态有限元分析(包括模态分析和瞬态分析),得到金属软管的任意阶固有频率,振型以及位移-时间曲线,并将分析结果与试验结果进行比较,证明了有限元建模及其分析结果的正确性,为金属软管的力学性能和设计分析尤其在防止共振方面的研究提供了参考.     

基于ANSYS的金属软管的静态有限元分析

运用非线性有限元法，波纹管采用三维壳单元Shell93，网套采用空间梁单元Beam189，利用耦合和约束理论，在ANSYS中建立金属软管的有限元模型，对金属软管的拉伸、压缩、弯曲等特性分别进行有限元分析，得到金属软管的特性曲线，并将分析结果与试验结果进行比较，证明了有限元建模分析结果以及耦合和约束理论运用的合理性，为金属软管的力学性能和设计分析的进一步研究提供了参考。     

船舶管路系统中金属软管动力学性能的有限元法研究

在ANSYS中建立了金属软管的动力学有限元模型,本文对金属软管的振动模态进行了仿真分析,并将分析结果与试验进行了对比,证明了动态有限元模型的可靠性,对金属软管的谐响应和瞬态振动响应进行了有限元仿真分析,分析结果对金属软管的设计、安装和使用具有非常重要的实用价值。     

船用承压金属软管平面失稳性能分析

在ANSYS中建立金属软管的有限元模型,对船用承压金属软管和波纹管的平面失稳性能进行了仿真分析,将其结果与试验结果进行对比,证明了有限元模型的可靠性。对船用金属软管在零位移、拉伸位移和压缩位移状态下的的平面失稳性能进行了有限元仿真分析研究。研究成果对提高金属软管的性能和船舶管路系统的质量以及金属软管结构的优化设计提供了非常有实用价值的参考。     

金属软管的网套及端部过渡波的有限元研究

对金属软管的网套进行非线性有限元分析，由于网套在受力时可以在波纹管上面既滚动又滑动，因此采用空间梁单元Beam189来表征网套的受力特性。将过渡波引入金属软管的有限元模型，对模型的端部进行修正，在此模型上，进行网套的静态特性分析，分析结果与试验结果符合较好，说明了有限元建模的有效性。     

基于ANSYS的金属软管参数化有限元建模方法

选用三维空间梁单元beam189表述网套钢丝,空间壳单元shell93表述波纹管,利用耦合节点的方法建立多层波纹管层与层之间的关系,用拟合理论推导出约束方程建立最外层波纹管与网套之间的关系,在ANSYS中建立金属软管的参数化有限元模型。利用此模型对金属软管进行轴线拉伸和压缩仿真分析,将其结果与试验结果进行对比,证明了有限元模型的可靠性。     

基于ANSYS的金属软管网套的有限元研究

运用非线性有限元法,利用ANSYS中的APDL语言,采用三维壳单元shell93和空间梁单元Beam189,采用耦合及约束方程理论,并考虑了端部小波对网套的影响,建立了合理的有限元模型,并将有限元计算结果与试验结果进行比较,进一步证明了有限元建模的正确性;文中提出了传统计算网套金属丝延长量的不足,给出了自己的看法,为金属软管的进一步研究提供了具有重要价值的结论。     

金属软管的静态有限元分析

对金属软管的拉伸、压缩、错动等特性分别进行有限元分析,得到了波纹管和网套的特性曲线,并且将分析结果与试验结果进行比较,证明了有限元建模的合理性,为金属软管的动态特性分析建立了可靠的有限元模型.     

Shot peening simulation based on SPH method

Shot peening is a complex surface-treating process which is usually employed to improve the fatigue strength of metallic part or members. In dealing with shot peening simulation, existing literatures apply finite element method (FEM) to establish only a single shot or several shots models, thus the effect of a mass of shots impacting repeatedly and the interaction among adjacent shots are ignored. To overcome these defects of FEM models, smoothed particle hydrodynamics (SPH) coupled FEM modeling is presented, in which the shots are modeled by SPH particles and the target material is modeled by finite elements. Contact algorithm is used to simulate the interaction between shots and target. Utilizing this model, material model for shots is established, the relationships between compressive residual stress and peening frequencies, coverage, and velocities are analyzed. Steady compressive residual stress can be gotten by multiple peening; higher coverage can improve the compressive residual stress; faster velocities can induce greater and deeper maximum residual stress in target subsurface. The simulation results agree well with the existing experimental data. The study will not only provide a new powerful tool for the simulation of shot peening process, but also be benefit to optimize the operating parameters.     

Advanced technique for non-destructive testing of friction stir welding of metals

In this paper a new non-destructive testing (NDT) system focusing on micro size superficial defects in metallic joints is presented. The innovative system is composed by a new type of eddy currents probe, electronic devices for signal generation, conditioning and conversion, automated mechanized scanning and analysis software. The key original aspect of this system is the new type of eddy currents probe. This new probe provides enhanced lift-off immunity and improved sensitivity for micro size imperfections. The probe concept was studied using a Finite Element Method (FEM) tool and experimental verified using a standard defect.     

The motion and deformation rate of a flexible hose connected to a mother ship

The motion of a flexible hose connected to a mother ship continually changes according to the motion of the mother ship. In such a case, telecommunication lines protected by the hose can give rise to serious problems like cutting or connecting error. It is very important to accurately analyze and predict the motion of an underwater flexible hose, because large deformation motions of the hose in axial and normal directions determine the vehicle’s driving conditions. In a realistic situation, it is difficult to carry out an experiment because the length of the hose is at least 10 m. Therefore, the behavior has to be predicted by computer simulation. In this paper, a mother ship was considered as a rigid body with six degrees of freedom driven at a specific rudder angle and surge propulsion velocity. And to model the flexible hose, absolute nodal coordinate formulation (ANCF) was adopted, whose formulation is accurate enough to express both the large deformation effect and various forms of behavior of the flexible hose. In ANCF, the concept of continuum mechanics is introduced to derive the tensile and bending stiffness of the hose. Hence, nonlinear effects of elastic forces can be considered more effectively. Fluid drag is also imposed, which has a significant effect on both the vehicle and the flexible hose.     

Nanobeam diffraction fluctuation electron microscopy technique for structural characterization of disordered materials—Application to Al88−xY7Fe5Tix metallic glasses

A fundamental experimental challenge in understanding the physical properties of non-crystalline (i.e., highly disordered) materials is that of fully characterizing the structural order that is present. Medium-range order is particularly difficult to characterize. Fluctuation electron microscopy (FEM) is a relatively new spatially resolved, diffraction technique that measures statistical fluctuations in the scattering of electrons arising from nanometer-scale ordered regions in a sample. The scattering fluctuations can be measured from dark-field (DF) images (the most common approach) or from a series of nanobeam diffraction (NBD) patterns. Here, the effectiveness of the NBD–FEM method for measuring atomic structure in disordered materials is evaluated. In particular, we show that the NBD–FEM statistical measures of fluctuations in diffraction intensity depend strongly on several instrumental parameters; measurement and analysis methodologies that constrain these parameters to minimize associated artifacts are presented. For illustration, the structure of the Al₈₈Y₇Fe₅ metallic glass is examined. It has been shown previously that the substitution of 0.5 at% Ti for the Al in this alloy significantly increases the glass forming ability. We provide NBD–FEM evidence indicating that the atomic structure of the glass is modified upon microalloying, in agreement with earlier extended X-ray absorption fine structure and high-energy X-ray diffraction studies.     

An ROV operated undersea hydraulic hose repair coupling

A hydraulic hose repair system is presented that was developed for use at the Deepwater Horizon accident site. The system can be deployed with a single ROV with two controllable arms. One arm holds the device and the other arm pushes a severed hose into the device. Hydraulic pressure is applied from the ROV to the device and a hydraulic coupling within the device is crimped into one end of the hose. The second hose end to be spliced to the first is pushed into the other side of the device and the second half of the coupling is crimped onto the second hose end. The device itself is left in place as part of the splice. The design, on-shore testing, and fabrication of multiple devices ready to deploy at the accident site took on the order of a week to complete. They stand ready to be deployed in the case of another deep-water accident.