对ROPES分析阶段的研究

利用ROPES分析阶段中需求分析、系统分析和对象分析技术,多方面分析了不同嵌入式系统的特点,从而可以确定合适的解决方案.

对ROPES设计阶段的研究

ROPES设计阶段的目标是在分析阶段的结果中添加了一些元素,在根据某些判定准则进行优化的基础上,从而确定一份特定的解决方案。架构设计能够给出可部署软件系统的大尺度软件分解;机制是对协作的具体化,将对象中这些机制结合在一起的过程就形成了机制设计;详细设计定义类的结构并对各个类的内部进行组织。

The finite element modeling of spiral ropes

Accurate understanding the behavior of spiral rope is complicated due to their complex geometry and complex contact conditions between the wires.This study proposed the finite element models of spiral ropes subjected to tensile loads.The parametric equations developed in this paper were implemented for geometric modeling of ropes.The 3D geometric models with different twisting manner,equal diameters of wires were generated in details by using Pro/ENGINEER software.The results of the present finite element analysis were on an acceptable level of accuracy as compared with those of theoretical and experimental data.Further development is ongoing to analysis the equivalent stresses induced by twisting manner of cables.The twisting manner of wires was important to spiral ropes in the three wire layers and the outer twisting manner of wires should be contrary to that of the second layer,no matter what is the first twisting manner of wires.

Analysis and control of vibration of ropes in a high-rise elevator under earthquake excitation

In this research, the vibration of elevator ropes, including the main rope and compensation rope are investigated simultaneously in a high-rise elevator system under earthquake excitation. Moreover, the paper presents a new control method to restrain the sway of both ropes. This study considers varying rope lengths during elevator operation which cause other system parameters such as natural frequency, and damping ratio to be time-variant variables. The dynamics of the ropes are analyzed by solving the governing non-stationary, nonlinear equation numerically. In order to mitigate the vibration of ropes in several motion conditions, particularly upwards movement, downward movement, stopped at the lowest position, and stopped at the highest position, an active equipment is installed at the compensation sheave. The stability of the system using the controller is analyzed at four states: without disturbance and static car, without disturbance and mobile car, including disturbance and static car, and including disturbance and mobile car. The efficiency of the controller used for dampening the vibration of elevator ropes is validated by numerical simulation results.

Know the Ropes

A good sailor knows all about ropes and how to tie theminto knots.From that we have this idiom,and it means toknow all there is about a job,a hobby,a business or a method.“You’ll never get to know the ropes if you continue to day-

Investigation into Failure in Mining Wire Ropes—Effect of Crystallinity

A range of blends of polypropylene-polyethylene are investigated for their mechanical performances. These speciality polymer blends are chemically designed to suit high modulus/high load bearing mining wire rope applications subjected to continued bending and tensile stresses and fluctuating loads and are exposed to extreme weather conditions. In this paper we study the influence of different parameters on the performance of the wire ropes: chemistry of polymer, crystallinity of the polymer matrix, and the morphology. The FTIR and SEM studies revealed that the high fraction of polypropylene in polypropylene-polyethylene matrix lead to early failure as a result of incompatibility and phase segregation and high spherulite sizes of the polymer matrix.

On the Thermal Conductivity of Single-Walled Carbon Nanotube Ropes

Recently measured thermal conductivity in single-walled carbon nanotube ropes in the temperature range 8 - 350 K has been explained using an anisotropic dynamical model which not only takes into account the quasi two-dimensional nature of the folded graphene sheets that forms the nanotubes, but also the intertube coupling, in addition to the phonon frequency and dimensionality dependent relaxation time of phonon-phonon scattering and interaction.

Dynamic design of a nonlinear energy sink with NiTiNOL-steel wire ropes based on nonlinear output frequency response functions

A novel vibration isolation device called the nonlinear energy sink(NES)with NiTiNOL-steel wire ropes(NiTi-ST)is applied to a whole-spacecraft system.The NiTi-ST is used to describe the damping of the NES,which is coupled with the modified Bouc-Wen model of hysteresis.The NES with NiTi-ST vibration reduction principle uses the irreversibility of targeted energy transfer(TET)to concentrate the energy locally on the nonlinear oscillator,and then dissipates it through damping in the NES with NiTi-ST.The generalized vibration transmissibility,obtained by the root mean square treatment of the harmonic response of the nonlinear output frequency response functions(NOFRFs),is first used as the evaluation index to analyze the whole-spacecraft system in the future.An optimization analysis of the impact of system responses is performed using different parameters of NES with NiTi-ST based on the transmissibility of NOFRFs.Finally,the effects of vibration suppression by varying the parameters of NiTi-ST are analyzed from the perspective of energy absorption.The results indicate that NES with NiTi-ST can reduce excessive vibration of the whole-spacecraft system,without changing its natural frequency.Moreover,the NES with NiTi-ST can be directly used in practical engineering applications.

Dynamic behavior of bridge-erecting machine subjected to moving mass suspended by wire ropes

The dynamic behavior of a bridge-erecting machine, carrying a moving mass suspended by a wire rope, is investigated. The bridge-erecting machine is modelled by a simply supported uniform beam, and a massless equivalent ＂spring-damper＂ system with an effective spring constant and an effective damping coefficient is used to model the moving mass suspended by the wire rope. The suddenly applied load is represented by a unitary Dirac Delta function. With the expansion method, a simple closed-form solution for the equation of motion with the replaced spring-damper-mass system is formulated. The characters of the rope are included in the derivation of the differential equation of motion for the system. The numerical examples show that the effects of the damping coefficient and the spring constant of the rope on the deflection have significant variations with the loading frequency. The effects of the damping coefficient and the spring constant under different beam lengths are also examined. The obtained results validate the presented approach, and provide significant references in the design process of bridgeerecting machines.

Principles of X-Ray Non-Destructive Testing for Steel Wire Ropes in Conveyer Belt

The principles of X-ray Non-destructive testing (NDT) for steel wire ropes buried in conveyer belt is described in the paper. The mathematical model for calculating the effective cross section of wire ropes has been developed. The test data on steel wire rope samples of various types are presented,which have been compared with the National Standard. And this calculation model for the effective cross section is very important to the prediction system for transverse failure of conveyer belt.

Morphology controllable growth of CaO/amorphous carbon ropes by a hydrothermal approach

A versatile hydrothermal strategy for the growth of a centimeter-sized CaO/amorphous carbon rope was introduced in this article. It is demonstrated that the centimeter-sized rope is composed of abundant amorphous carbon ＂belt＂ and ＂stick＂ with small polygonal CaO particles in the size of 3.0-5.0 nm embedded in the ＂belt＂ and ＂stick＂ framework. With the increase in NaOH amount, polygonal Ca（OH）2 particles in the size of 0.5-3.0 μm are found, instead of the CaO/amorphous carbon rope. This morphology evolution results from the competition of structure-directing and hydrothermal-carbonizing of organic agents during hydrothermal reaction. These results may give good suggestions for the controllable growth of newly unique morphological micro/nano architectures in solution phase reactions.

聚酯缆动力学行为计算方法研究

The dynamic stiffness of polyester rope presents a complex mechanical performance,and the search for an appropriate calculation method to simulate this property is important.Distorted simulation results eventually yield inaccurate line tension and vessel offset predictions,with the inaccuracy of vessel offset being particularly large.This paper proposes a flexible calculation method for the dynamic behavior of polyester rope based on the dynamic stiffness model.A real-time varying stiffness model of polyester rope is employed to simulate tension response through rope strain monitoring.Consequently,a simulation program is developed,and related case studies are conducted to explore the differences between the proposed method and analytical procedure of the DNV standard.Orcaflex is used to simulate the results of the latter procedure for comparison.Results show the convenience and straightforwardness of the procedure in the selection of an approximate dynamic stiffness model for polyester rope,which leads to an engineering-oriented approach.However,the proposed method is related to line property,which can directly reflect the dynamic behavior of polyester rope.Thus,a flexible calculation method may provide a reference for the simulation of the dynamic response of polyester mooring systems.

Catastrophe of coronal magnetic flux ropes in fully open magnetic field

The catastrophe of coronal magnetic flux ropes is closely related to solar explosive phenomena, such as prominence eruptions, coronal mass ejections, and two-ribbon solar flares. Using a 2-dimensional, 3-component ideal MHD model in Cartesian coordinates, numerical simulations are carried out to investigate the equilibrium property of a coronal magnetic flux rope which is embedded in a fully open background magnetic field. The flux rope emerges from the photosphere and enters the corona with its axial and annular magnetic fluxes controlled by a single "emergence parameter". For a flux rope that has entered the corona, we may change its axial and annular fluxes artificially and let the whole system reach a new equilibrium through numerical simulations. The results obtained show that when the emergence parameter, the axial flux, or the annular flux is smaller than a certain critical value, the flux rope is in equilibrium and adheres to the photosphere. On the other hand, if the critical value is exceeded, the flux rope loses equilibrium and erupts freely upward, namely, a catastrophe takes place. In contrast with the partly-opened background field, the catastrophic amplitude is infinite for the case of fully-opened background field.

Aeroelastic Properties and Nonlinear Vibration Control of a Simply-Supported Lattice Sandwich Beam Embedded with Nitinol-Steel Wire Ropes

As a novel vibration absorber,Nitinol-steel wire rope(NiTi-ST)has rarely been studied on vibration suppression for lattice sandwich beams in supersonic airflow.In this paper,NiTi-ST with nonlinear stiffness and hysteretic damping is embedded in a lattice sandwich beam to control the beam's vibration.The nonlinear restoring and hysteretic damping force of NiTi-ST are treated as polynomials.The dynamic equation is established based on Hamilton's principle.The amplitude responses of the beam with different NiTi-ST configurations are calculated.The vibration-suppression effects and energy dissipation of lattice sandwich beam with different NiTi-ST configurations under different air velocities are also compared.The frequency-domain and time-domain methods are used to analyze the structural aeroelastic properties.Simulation results show that the use of NiTi-ST can significantly suppress excessive vibration of a lattice sandwich beam in supersonic airflow.

A comparison of hydrodynamic forces in knotted and knotless netting,using both helix and conventional ropes for midwater trawls

This study evaluated the hydrodynamic forces produced by whole panels of hand-made(geometrically different)rope meshes typically found in midwater trawls.Experimental treatments included both knotted and knotless meshes constructed of helix composite ropes,conventional braided nylon(PA)ropes,and twisted polyethylene(PE)ropes.Direct measurement of lift(L)and drag(D)forces were conducted using controlled flume tank experiments on panels oriented at 21°relative to the flow.For knotted netting,our results showed that the hydrodynamic forces(L and D)were statistically higher for helix ropes compared to conventional ropes of the same diameter.For knotless netting constructed of helix ropes,our primary finding is that the arrangement of helix ropes(S and Z lay)in individual meshes significantly affects the resulting D and Cd of whole netting panels.Arranging the mesh bars in the S-Z-S-Z lay pattern exhibited 29%and 32%lower drag(D)compared to S–S–S–S and S–S-Z-Z lay meshes,respectively.We also use computational fluid dynamics(CFD)to characterize the finescale flow-field around helix and conventional ropes.The resulting streamlines and pressure contours provide a functional explanation for the empirical measurements collected in the flume tank.These results can be useful in informing the design of midwater trawls.

解剖型锁定钢板联合TightRope内固定治疗锁骨远端骨折的效果

目的:探讨解剖型锁定钢板联合Tight Rope内固定治疗锁骨远端骨折的效果。方法:回顾分析常熟市第二人民医院创伤骨科2015年4月—2021年6月收治的93例锁骨远端骨折患者,按其治疗方式分对照组(n=46)和观察组(n=47)。对照组接受锁骨钩钢板内固定治疗,观察组接受解剖型锁定钢板联合Tight Rope内固定治疗。比较两组患者围手术期指标、肩关节功能、骨形成蛋白-2(BMP-2)、凝血指标、并发症发生率。结果:两组术中出血量比较,差异无统计学意义(P>0.05);观察组手术时间长于对照组,但骨折愈合时间、术后住院时间均短于对照组,差异均有统计学意义(P<0.05)。术后1、3个月,观察组肌力、肩关节活动度、日常活动、疼痛评分均高于对照组,差异均有统计学意义(P<0.05)。术后1周,观察组BMP-2、凝血酶原时间(PT)均高于对照组,纤维蛋白原(FIB)、D-二聚体(D-D)均低于对照组,差异均有统计学意义(P<0.05)。观察组并发症发生率(4.26%)低于对照组(21.74%),差异有统计学意义(P<0.05)。结论:相比于锁骨钩钢板内固定术,解剖型锁定钢板联合Tight Rope内固定术治疗锁骨远端骨折的效果更理想,在患者术后肩关节功能恢复、骨折愈合、并发症控制等方面均有明确优势。

小切口复位Tight Rope纽扣钢板内固定治疗RockwoodⅢ型肩锁关节脱位的效果观察

目的:探讨小切口复位Tight Rope纽扣钢板内固定治疗RockwoodⅢ型肩锁关节脱位的效果。方法:选取89例RockwoodⅢ型肩锁关节脱位患者,按照随机数字表法将其分为两组。对照组44例,采用锁骨钩钢板内固定术,观察组45例,采用小切口复位Tight Rope纽扣钢板内固定术,观察两组手术相关指标、肩关节功能、疼痛程度、创伤应激指标及并发症发生率。结果:观察组手术相关指标优于对照组,术中出血量少于对照组,差异有统计学意义(P<0.05);术后1 d,观察组CMS各维度得分高于对照组(P<0.05);术后1 d、3 d、7 d,观察组VAS评分均低于对照组(P<0.05);术后,两组Cor、ACTH均升高,且观察组低于对照组(P<0.05);观察组并发症发生率6.67%低于对照组20.45%(P<0.05)。结论:小切口复位Tight Rope纽扣钢板内固定治疗RockwoodⅢ型肩锁关节脱位,减少手术创伤,缩短手术时间,减轻疼痛,安全性较好。

空心钉与Tight Rope内固定治疗Lisfranc损伤的对比分析

目的 对比分析空心钉与Tight Rope内固定治疗Lisfranc损伤的效果。方法 将2020年1月-2021年6月在本院骨科治疗的74例Lisfranc损伤患者随机分为两组,对照组使用空心钉内固定治疗,观察组使用Tight Rope内固定治疗,对比两组的手术疗效、并发症、疼痛、AOFAS评分。结果 对比Lisfranc损伤恢复优良率,观察组更高,恢复更好(P<0.05);切口感染、内固定松动、内置物断裂、足背部浅感觉减退、跖跗关节不稳、创伤性关节炎等并发症相比,观察组的发生概率均更低(P<0.05);术后1个月、6个月、12个月的VAS疼痛评分相比,两组前两个时间点相当(P>0.05),而术后12个月观察组更低(P<0.05);术后1个月、6个月、12个月的AOFAS评分中疼痛、功能、患足力线相比,两组前两个时间点相当(P>0.05),而术后12个月观察组均更高(P<0.05)。结论 Tight Rope内固定治疗Lisfranc损伤的效果更好,远期疼痛更轻,功能恢复更好,并发症发生率更低,整体手术疗效优于空心钉内固定。

带线锚钉与Tight Rope钢板治疗肩锁关节脱位的临床效果研究

目的:比较带线锚钉与Tight Rope钢板治疗肩锁关节脱位的临床效果。方法:回顾性分析72例肩锁关节脱位患者的临床资料,根据患者的治疗方式分组,其中36例患者接受带线锚钉治疗,36例患者接受Tight Rope钢板治疗,比较两组治疗效果。结果:Tight Rope钢板组的手术时间、住院时间与康复周期短于带线锚钉组,出血量少于带线锚钉组(P<0.05);Tight Rope钢板组术后RoWE功能评分高于带线锚钉组(P<0.05);两组间隙距离差异无统计学意义(P>0.05)。结论:带线锚钉与Tight Rope钢板均可有效治疗肩锁关节脱位,且Tight Rope钢板造成治疗创伤更小,有利于术后康复。