Stress Of Steel Wire Research Articles

Influence of coiling behavior on axial stress in steel wires of submarine power cables: A numerical study

Coiling processes that are commonly employed to lay submarine power cables to static tanks on ships cause twisting and bending deformations of the cables, potentially affecting the integrity and safety. This study investigates the mechanical behavior of submarine power cables subjected to combined torsional and bending loads using analytical models and finite element method-based software. The objective of the numerical analysis was to evaluate compressive stresses generated within the armor wires of submarine power cables. Additionally, the investigation was extended to assess the potential risk of wire buckling, i.e., bird-caging. The influence of wire pitch length and tank diameter on the magnitude of compressive stress was examined, and the findings revealed a decrease in the likelihood of wire buckling with longer pitch lengths and larger tank diameters. The results of this study will offer valuable insights into the cross-sectional design and the mechanical behavior of submarine power cables subjected to coiling operation.

Armored steel wire stress monitoring strategy of a flexible hose in LNG tandem offloading operation

Cryogenic flexible hose is the key equipment for tandem offloading operation of Floating Liquefied Natural Gas (FLNG). The harsh marine environment leads hulls motion responses and complex hose motion characteristics during the tandem offloading, thus causing various failure behaviors of the entire hose. In this paper, a combined global-local monitoring strategy for armored steel wire stress distributions in cryogenic flexible hose is proposed. High-precision flexible hose governing equations are established by using the function to fit the relationship between the vertical force and the hose length. A reasonable monitoring strategy is given based on the pipeline configuration variations and sensor accuracy. Real-time monitoring of the flexible hose from the global (hose) to the local (armored steel wire) during the tandem offloading is carried out by installing sensors in specified locations on hulls and hose segments. The tandem offloading operation under different (static, calm and harsh) sea states is modelled by Orcaflex software. An armored steel wire model is developed using ABAQUS software. Comparisons of the pipeline configurations, curvatures, axial forces and maximum wire stresses are made with the simulation results to verify the feasibility of the monitoring strategy. The results show that the proposed monitoring strategy in this paper can accurately and effectively obtain the hose motion characteristics and maximum stress states of armored steel wires under different sea states, and can evaluate the hose structural safety in real time during the tandem offloading operation.

Long-Term Loading Experimental Research of Prestressed Glulam Beams Based on Creep Influence

In this paper, long-term loading tests of ten prestressed glulam beams were carried out for 45 days, using the loading method of three-point hanging heavy objects. We analyzed the influence of prestressed steel wire numbers and total preloading force on parameters such as failure mode of beams, variation of steel wire stress, and long-term deflection of mid-span. When the total prestress was constant and the number of steel wires was 2, 4, and 6, the total stress of steel wires decreased by 33.07%, 37.26%, and 50.04%, respectively, after long-term testing for 45 days. The ratio of mid-span deflection to total deflection was 61.5%, 54.8%, and 40.9% respectively. When the number of steel wires was constant and the values of total prestress were 0, 3.079 kN and 6.158 kN, the total stress decreased by 28.90%, 36.59%, and 36.63%, respectively, after long-term loading. The ratio of long-term deflection of mid-span to total deflection was 60.7%, 54.8%, and 39.3%, respectively. The more steel wires, the greater the value of total prestress and the loss of total stress, the smaller the mid-span long-term deflection. After the test, we analyzed and fitted the test data to obtain the specific numerical of the creep coefficient θ under normal conditions, and the formula for calculating the long-term stiffness of the glulam beams based on the creep effects is proposed.

Study on flexural performance of prestressed glulam continuous beams under control influence

Traditional glulam beam connection mode has a weak ability to transfer bending moment, leading to insufficient joint stiffness and mostly in the form of simply supported beams. To make full use of material strength, a novel prestressed glulam continuous beam was proposed. On this basis, this paper put forward a new method to further improve the mechanical performance of the beams by controlling prestress. According to the estimated ultimate loads of the beams, six different control range values were formulated, and 12 continuous beams were tested for flexural performance. The effects of prestressing control on the failure modes, ultimate load capacity, and load versus deformation relationships of the glulam continuous beams were analyzed. The test results indicated that the flexural performance of the beams with prestressed control was significantly improved compared to the uncontrolled beams, the ultimate load was enhanced by 13.60%–45.11%, and the average steel wire stress at failure was increased from 70% of the designed tensile strength to 94%. Combined with the finite element analysis (FEA), the reasonable control range of the prestressed control continuous beams was18%–30% of the estimated ultimate load. The research in this paper can provide references for the theoretical analysis and engineering application of similar structures.

Finite element study of behaviour and interface force conditions of locked coil wire rope under axial loading

As a new type of cable with excellent mechanical properties, the research on the mechanical properties of the locked coil wire rope is very scarce. Owing to its special section form and steel wire contact mode, the mechanical properties of the locked coil wire rope are significantly different from those of traditional cables. In this paper, based on the ABAQUS/Explicit platform, a refined modelling method of the locked coil wire rope is proposed considering real anchorage characteristics. The purpose is to study the mechanical properties, stress distribution, interface force conditions between steel wires, and failure process of the locked coil wire rope under axial load. Based on the Feyrer theory calculation method, the stress distribution law of steel wires in the tension process of the locked coil wire rope is studied, and its failure criterion is proposed. It is found that the steel wire stress distribution is uneven in the process of cable tension. The stress of the central steel wire is greater than that of the surrounding steel wires. Cable failure generally occurs at the end. The friction between the steel wires has little effect on the tensile process, but the quality of the anchorage end affects the ultimate strength of the cable.

Analysis on the design of steel wire wound extrusion containers for hot extrusion process

Extrusion container is the most important tooling for steel hot extrusion process. Conventional design using large castings and forgings is very difficult to execute due to high cost and risk. Steel wire wound containers have many advantages over conventional designs. However, conventional wire wound containers are developed for use at room temperature which are not applicable to steel hot extrusion process. In this article, the impacts of preheating on the design of steel wire wound containers are discussed in detail. A finite element model was established to examine the preheating temperature distribution, and a 1:10 scaled extrusion container was manufactured to verify the effectiveness of the finite element model. Based on the finite element model–computed temperature field, thermal stress analysis was performed. The thermal impacts on the stress of extrusion container and steel wire were obtained. Results showed that insufficient stability of internal cylinder and greatly enhanced steel wire stress may lead to the failure of extrusion container. To solve the problems, an improved design was put forward by increasing the stability factor of internal cylinder, reducing the prestress factor and lowering the allowable stress of steel wire. Results showed that the improved design can meet the requirements and counteract the thermal impacts.

Research on Monitoring Force of Steel Wire Rope of Grab Dredger Base on Wireless Sensing

The article research on intelligent grab dredger. Work force mechanical model of steel wire is established during dredging Grab's flat digging working. Then, the theoretical calculation on stress of the steel wire is available. It's easy to get the result of dredging Grab's steel wire. Meanwhile, a way is put forward about changing the rotating shaft torque to the force of steel wire, which is based on detection of wireless sensor network technology in grab dredger's hoist. The ideal result on Real-time display of the curves of closing hoist and hoist rope's stress. The test result of real-time monitoring show that the theoretical calculation on stress of the steel wire is consistent with the test result of real-time monitoring, which provide the basis on the application of real-time monitoring of wireless sensor technology in the grab dredger's steel wire's stress.

Dynamic torsional characteristics of mine hoisting rope and its internal spiral components

Dynamic torsional characteristics of mine hoisting rope and its internal spiral components were investigated in the present study. Theoretical models of tensions of rope segments at distinct locations were presented to obtain dynamic rope tensions. Theoretical models of torque, unit torsion angle, torsion angle, twisting parameters, and torsional stress were introduced to investigate dynamic torsional characteristics of hoisting rope and its internal spiral components under tension. Rope tests were conducted in order to validate dynamic torsional properties of the rope under fluctuation tensions. The results show three-stage fluctuating trends of rope tension and torque. An increase of hoisting time induces a decreased torsion angle of the rope, fluctuating upward trends of unit torsion angles of the rope, spiral strands and steel wires, respectively, fluctuating increases in lay angles of the spiral strand and steel wires, respectively, and the fluctuating decreased lay length of the spiral strand. An increase of the distance between rope segment and friction pulley tangent causes a decrease at first and then an increase in the unit torsion angle in cases of the rope, spiral strands and steel wires, an increase at first and then a decrease in the rope torsion angle, increased lay angle and decreased lay length of the spiral strand, a decrease at first and then an increase in the torsional stress of steel wire in every layer of the spiral strand.

A Steel Wire Stress Measuring Sensor Based on the Static Magnetization by Permanent Magnets.

A new stress measuring sensor is proposed to evaluate the axial stress in steel wires. Without using excitation and induction coils, the sensor mainly consists of a static magnetization unit made of permanent magnets and a magnetic field measurement unit containing Hall element arrays. Firstly, the principle is illustrated in detail. Under the excitation of the magnetization unit, a spatially varying magnetized region in the steel wire is utilized as the measurement region. Radial and axial magnetic flux densities at different lift-offs in this region are measured by the measurement unit to calculate the differential permeability curve and magnetization curve. Feature parameters extracted from the curves are used to evaluate the axial stress. Secondly, the special stress sensor for Φ5 and Φ7 steel wires is developed accordingly. At last, the performance of the sensor is tested experimentally. Experimental results show that the sensor can measure the magnetization curve accurately with the error in the range of ±6%. Furthermore, the obtained differential permeability at working points 1200 A/m and 10000 A/m change almost linearly with the stress in steel wires, the goodness of linear fits are all higher than 0.987. Thus, the proposed steel wire stress measuring sensor is feasible.

Torsion Failure Analysis of 0Cr17Ni7Al Precipitation Hardening Stainless Steel Wire

0Cr17Ni7Al is a precipitation hardening stainless steel, which combines the advantages of austenitic stainless steel and martensitic stainless steel. 0Cr17Ni7Al shows good corrosion resistance, excellent processability and high strength. This paper is mainly focused on the fracture morphology of 0Cr17Ni7Al wire during torsional deformation. Cracking mechanism and torsion failure reason is analyzed in detail. The results show that AlN inclusions are observed both in raw steel wire and fracture, the micro-cracks appear along the axial direction of the steel wire. The torsion strength is normally 2958MPa. but, the local stress of steel wire reaches up to5295MPa when a 0.4mm deep micro-crack locates on the surface of steel wire, and the local stress is obtained to 2953MPa around a 10μm AlN inclusion. Stress concentrating is caused by inclusions and micro-cracks, and the crack propagation lead to the torsion failure of steel wire when the local stress is beyond the torsion limit.

Nonlinear Finite Element Analysis of FQQB

The mechanical properties of the whole wall and the wall with openings under vertical loads are analyzed by nonlinearity finite element method (NFEM). The results show that the stress of steel wire has a direct relationship with the load form. The inclined plug wire mainly carries the stress caused by load differences between the two sides of concrete, it makes both sides of concrete work together better. As the diameter of the inclined plug wire increased, the effects on the FQQB mechanical properties become greater, wire mesh stress on both sides decrease, and the vertical displacement of FQQB decrease. Cracks appear above the openings of FQQB which has been cut holes. Steel wire tends to be tension stress concentrated, and there are obvious stress concentration belts on both sides of the opening. However, the size of the opening has little effects on the ultimate bearing capacity of wall panel.

Research on stress distribution between wires of single thigh steel strand

A three-dimensional contact model of 1×7 steel strand was established. Contact point was searched by Splitting-pinball algorithm, and Augmented-Lagrangian algorithm was applied for analysis of contact loads. The exerted tensile loads to the model were analyzed using finite element method. After analyzing calculation results, the laws of steel wire stress distribution in axis direction and in its cross-section were found. Friction coefficients were set as 0.10, 0.11, and 0.12, respectively, to obtain the influence law of friction coefficient to steel wire stresses. Research result shows that friction coefficient has significant influence on the shear stress of steel wire. Analyzed the calculation results of steel strand with five different lay pitch multiples and got the influence law of lay pitch multiple to the stresses of steel wire in steel strand. The Von Misses stress of steel wire increases following with the increasing of lay pitches multiples, but the increment value is not very prominent. The shear stress of steel wire decreases following the increase of lay pitch multiple, and the changing amplitude is large when lay pitch multiple is small. Finally, carried out a steel strand tensile deformation test and the consistency of test results with the calculation results shows that the selected model is reasonable.

Monitoring based maintenance utilizing actual stress sensory technology

In recent years, many infrastructures have been deteriorating. In order to maintainsustainability of those infrastructures which have significant influence on social lifelines,economical and rational maintenance management should be carried out to evaluate the lifecycle cost (LCC). The development of structural health monitoring systems, such asderiving evaluation techniques for the field structural condition of existing structures andidentification techniques for the significant engineering properties of new structures, can beconsidered as the first step in resolving the above problem. New innovative evaluationmethods need to be devised to identify the deterioration of infrastructures, e.g. steeltendons, cables in cable-stayed bridges and strands embedded in pre- or post-tensionedconcrete structures. One of the possible solutions that show ‘AtoE’ characteristics, i.e.,(a)ccuracy, (b)enefit, (c)ompendiousness, (d)urability and (e)ase of operation,elasto-magnetic (EM) actual stress sensory technology utilizing the sensitivity ofincremental magnetic permeability to stress change, has been developed. Numerousverification tests on various steel materials have been conducted. By comparingwith load cell, strain gage and other sensory technology measurement results,the actual stresses of steel tendons in a pre-stressed concrete structure at thefollowing stages have been thoroughly investigated: (i) pre-stress change due toset-loss (anchorage slippage) at the tendon fixation stage; (ii) pre-stress changedue to the tendon relaxation stage; (iii) concrete creep and shrinkage at the longterm pre-stressing stage; (iv) pre-stress change in the cyclic fatigue loading stage;and (v) pre-stress change due to the re-pre-stress setting stage. As the result ofthis testing, it is confirmed that EM sensory technology enables one to measureactual stress in steel wire, strands and steel bars precisely without destroying thepolyethylene covering sheath and enables one to provide adequate accuracy andreliability for monitoring actual stresses of those steel tendons during the life cycle ofinfrastructures. An example of a field application at a cable-stayed bridge is described.

The measurement of the axial internal stress in steel wire

Apparatus is described for the measurement of the approximate axial internal stress distribution in wires typically 0·3–0·4 mm diameter. A sensitive optical system measures the change of length of the wire as its diameter is reduced at a rate of about 0·3 μm per minute by dissolution in 0·012 M nitric acid maintained at a constant temperature. The change of area of cross section of the wire is deduced from measurement of its electrical resistance. The adoption of a continuous thinning process makes it possible to measure the internal stress at the original wire surface. The method is not able to take account of the effect on the axial strain of the relief of circumferential and radial stresses. This leads to the axial stress being underestimated by about 30%. Internal stress measurements are reported on patented and drawn steel wire which confirm the wide range of internal stress intensity that can be generated in this material by changing and drawing conditions.