碳纤维复合材料自行车车架轻量化设计

文中考虑到碳纤维增强复合材料轻质高强的特点,利用灰色关联分析方法对碳纤维增强复合材料自行车车架开展铺层优化设计。通过材料力学性能试验获得碳纤维增强复合材料力学性能参数,并建立碳纤维增强复合材料自行车车架有限元模型,结合正交试验设计与灰色关联分析法,综合考虑自行车车架的质量、模态频率、强度和刚度等性能指标,对碳纤维增强复合材料自行车车架进行铺层厚度和角度优化设计。优化后,与原钢质自行车车架相比,在满足性能要求的前提下,CFRP自行车车架减重78.85%,取得了较好的轻量化效果。     

某轿车副车架轻量化

为满足副车架轻量化要求,同时保证副车架的动、静态性能,采用碳纤维材料替换原钢质材料的方式。对轿车原副车架进行静力分析及模态分析,在保证碳纤维车架动、静态性能的条件下,对碳纤维材料铺层角度及各层厚度进行优化,并将碳纤维车架与原车架静力分析结果进行对比。结果表明:碳纤维副车架模型的静、动态性能达到了设计要求,质量减轻了89.15%,轻量化效果明显。     

承载式碳纤维缠绕内衬钢管车架轻量化设计

使用碳纤维增强复合材料(Carbon Fiber Reinforced Polymer,CFRP)替换原金属材料是汽车轻量化设计的新途径。对于连接要求高、空间结构复杂的车架结构采用碳纤维缠绕内衬钢管的形式来实现材料的部分替代是一种新的思路。以承载式CFRP层缠绕内衬钢管车架为研究对象,在保证车架安全性的前提下,基于HyperWorks软件的复合材料优化模块,通过自由尺寸优化、厚度参数优化和铺层顺序优化3个步骤对CFRP层进行质量寻优;考虑承载式CFRP层缠绕内衬钢管车架的制造工艺性,对CFRP层的优化结果进行调整以满足制造要求。优化后,承载式车架质量较原钢制车架质量减少了23%,且在满载弯曲、急刹车、急转弯和侧翻等极端工况下满足刚度和强度要求。     

机床用碳纤维传动轴设计与分析

根据机床传动轴的设计参数,设计了碳纤维传动轴,确定了铺层层数及厚度.在此基础上,根据碳纤维布的铺层原则,制定了6种铺层方案,通过比较几种方案的变形和应力分布,从中选取最优铺层方案.运用ANSYS有限元仿真软件,对设计的碳纤维复合材料传动轴,进行静态扭转分析和模态分析,得到其扭转性能参数和固有频率,根据仿真结果可知设计的碳纤维传动轴能够满足机床传动轴的使用要求.     

不同铺层方式的复合材料层合板弯曲性能的研究

以碳纤维缠绕电动节能车车架为研究对象,采用有限元分析和力学试验对比的方式研究碳纤维铺层角及铺层层数对碳纤维复合材料层合板弯曲性能的影响。以层合板铺层角度、铺层层数为变量设置试验对比组,在ANSYS Composite Prep/Post复合材料分析模块中创建层合板的有限元模型研究层合板在承受弯曲载荷时的抗弯表现。结合弯曲试验结果,分析不同铺层方式对碳纤维复合材料层合板弯曲性能的影响。结果表明:在铺设一定数量的±45°铺层的基础上,增加0°/90°正交铺层可提高层合板的静承载强度;增加铺层层数,可提高层合板的弯曲强度。     

基于COSMOS技术的轻轨巡检车车架的有限元分析

在SolidWorks软件中,建立了国内第一辆自行研制的轻轨巡检车的三维实体模型;再调用SolidWorks的有限元模块--COSMOS,得到该车架的有限元模型.利用COSMOS软件分析了该车架在重庆轻轨实际运用中3种不同工况下的静态特性.分析结果表明该车架的设计方案是可行的.     

天线反射面的冲击变形仿真

树脂基碳纤维复合材料（CFRP）产品具有轻质、高强度、高刚度等特点.文中从刚度设计的角度出发,对碳纤维复合材料天线反射面进行铺层设计,利用有限元分析软件ANSYS对其冲击变形仿真,结果表明所有铺层方式均满足设计要求,但实际铺层时应考虑采取变形最小的准各向同性铺层[90/45/9/-45/-A]s.     

修井机车架有限元分析

根据修井机使用的环境、配套设备的尺寸要求及交通运输车辆国标对修井机车体进行了整体设计,包括汽车型式、主要尺寸和参数的设计。利用SolidWorks三维建模软件建立车架的仿真模型。根据平衡悬架的性能,建立了平衡悬架的三种模型并分析了三种模型的瞬态动响应特性,找到最符合平衡悬架特性的模型。应用有限元分析软件ANSYS对车架进行简化并与平衡悬架进行结构静力学联合仿真,校核设计的车架是否符合修井机的使用要求。     

自行车车架接头结构的研究

青岛自行车公司金鹿牌载重自行车长期以来存在较严重的车架疲劳冲击检定不合格现象,据80、81、82三年统计,车架有关部位冲击检定断裂率平均在17%以上,零件二厂质检情况更差一些。断裂主要原因:一是平口接头(有衬管)是一种极不合理的结构形式,二是衬管焊接缺陷不易克服(焊成率国内水平是75%)。本文对现有几种接头结构进行了力学电测和光弹分析,并用正交实验的方法,选取了一种优化接头结构,青岛自行车公司准备在第三代大金鹿自行车车架上采用这种接头。现将情况介绍如下。一、自行车车架各种接头形式的研究 1.各种接头形式关于自行车车架接头合理形式的探讨,国内外已有不少专家进行过研究,从国内外各种自行车广告、杂志、样本和论文中可以看到,车架接头形式除了平口接头外大体上有下列五种形式:鸟咀形、鸭咀形、扣花鸟咀形、河蚌形(鱼尾形)、花边形,见图1所示。     

碳纤维复合材料传动轴的仿真分析

碳纤维复合材料密度低、比强度和比模量高等良好的力学性能,已经广泛应用于航空、汽车、建筑业、医疗器材等各个领域。采用有限元分析软件对碳纤维传动轴进行分析,传动轴受扭转载荷情况下,针对不同铺层对碳纤维传动轴的应力分布情况进行分析。     

Comparison of prediction methods for damping of a symmetric balanced laminated composite beam

To determine the effective damping of a symmetric, balanced laminated composite, three different analytical models were compared. In the first model, Adams and Ni's theory was used. In the second model, modified classical lamination theory based upon the clastic viscoelastic correspondence principle was used. In the third model, and energy approach was developed to investigate the damping of laminated composite beams. Four typical laminated composites with [±g]s, [0/±θ]s, [0/θ]s and [0/±θ/90]s stacking sequences were employed for this study.     

Solid particle erosion of CFRP composite with different laminate orientations

The solid particle erosion behavior of epoxy base unidirectional and multidirectional carbon fiber reinforced plastic composites was investigated. The erosion rates of these composites were evaluated at various impingement angles (15–90°) with a particle velocity of 70 m/s. Irregular SiC particles with an average diameter of 80 μm was used. The dependence of impingement angle on the erosive wear resembled the conventional ductile behavior with maximum erosion rate at 15–30° impingement angle. The erosion rate of unidirectional composites at acute impingement angle was higher for [90] than for [45] and [0] while the difference disappeared at normal impingement angle (90°). On the other hand, the erosion rates of multidirectional laminated composites ([0/90], [45/−45], [90/30/−30] and [0/60/−60]) were not much influenced by the fiber orientation except for 15° impingement angle.     

The estimation of the diameter error in bar turning: a comparison among three cutting force models

Machining accuracy is considerably affected by the deflection of the machine-tool-workpiece system under the action of the cutting force. A new model to estimate a bar diameter error due to the deflection of the tool, of the workpiece-holder and of the workpiece was defined by the authors, starting from a cutting force model. This work deals with a comparison among the bar diameter errors that are calculated by means of the developed model involving three different cutting force models. The considered cutting force models were the specific cutting resistance, the Kronenberg cutting force and the unified-generalised mechanics of the cutting force model developed by Armarego. The numerical results were compared with those obtained by experimental tests carried out through a parallel lathe. The results show that the Armarego's cutting force model provides values of the force components and, therefore, the values of the resulting bar diameter errors are closest to the experimental ones.Nomenclature a The longitudinal position of the tool, [mm] - a_pn The nominal depth of cut, [mm] - a_p The real depth of cut, [mm] - b The width of area of cut, [mm] - A The tool-workpiece interference area of cut, [mm²] - AB The generalised cutting edge vector - A_r The area of the workpiece cross section, [mm²] - c_s The spindle compliance, [mm/N] - c_t The tailstock compliance, [mm/N] - c_tht The tangential toolholder compliance, [mm/N] - c_thr The radial toolholder compliance, [mm/N] - D The workpiece diameter, [mm] - E The modulus of elasticity, [N/mm²] - f The feed, [mm/r] - F_rad The radial component of the cutting force, [N] - F_feed The feed component of the cutting force, [N] - F_{tan g} The tangential component of the cutting force, [N] - F_i The resultant of F_feed and F_{tan g}, [N] - G The shear modulus, [N/m²] - h The thickness of the area of the cut, [mm] - I The workpiece moment of inertia, [mm⁴] - L The workpiece length, [mm] - P_i The plane containing the inflected curve of the workpiece - P_f The tool assumed working plane - P_n The cutting edge normal plane - P_nG The generalised cutting edge normal plane - P_r The tool reference plane - r_l The chip length ratio - R The workpiece radius, [mm] - R_b The tailstock reaction force, [N] - R_s The spindle reaction force, [N] - S The shape factor - v_c The cutting speed, [mm/min] - v_e The resultant cutting speed, [mm/min] - v_f The feed speed, [mm/min] - v_ch The chip speed, [mm/min] - v_sh The shear speed, [mm/min] - w(z) The total deflection of the workpiece axis, [mm] - w_a The total displacement of the workpiece axis from z reference axis measured in P_i plane, [mm] - (z) The orientation of P_i with respect to F_rad and F_{tan g}, [degree] - The friction angle, [degree] - _n The normal friction angle, [degree] - _nG The generalised normal friction angle, [degree] - The shear factor - _n The normal shear angle, [degree] - _NG The generalised normal shear angle, [degree] - _f The tool side angle, [degree] - _n The tool normal rake angle, [degree] - _nG The generalised tool normal rake, [degree] - _P The tool back angle, [degree] - _c The chip flow angle, [degree] - _cG The generalised chip flow angle, [degree] - _r The tool cutting edge angle, [degree] - _rG The generalised tool cutting edge angle, [degree] - _s1 The tool cutting edge inclination, [degree] - _s2 The inclination of the secondary tool cutting edge [degree] - _sG The generalised tool cutting edge inclination, [degree] - The friction coefficient - The work material shear stress, [MPa] - _r The tool approach angle, [degree] - The approach angle of the secondary cutting edge, [degree]     

Interlaminar stresses of a rectangular laminated plate with simply supported edges subject to free vibration

The interlaminar stresses in a laminated rectangular orthotropic plate with four sides simply supported edges during free vibration was determined by using the integration method involving the dynamic inertia terms and displacements. The approximate stresses solutions are obtained under the effect of frequencies of vibration for four-layer symmetric cross-ply laminates with the ply configurations [0°/90°]_s and [90°/0°]_s, angle-ply laminates with the ply configuration [45°/−45°]_s. Numerical results show that the natural frequency has significant effects on the dominant interlaminar stresses in the stacking sequences [0°/90°]_s, [90°/0°]_s and [45°/−45°]_s.     

Impact of stacking sequence on tribological wear performance of woven jute-glass hybrid epoxy composites

Natural fibre-reinforced plastic (FRP) composites have gained much interest because of their environment friendliness and cost-effectiveness compared to synthetic fibre-reinforced composites. The availability of natural fibre and ease of manufacturing have tempted researchers worldwide to develop a locally available low-cost fibre and study their feasibility for reinforcement purposes and to what extent they can satisfy the required specifications of well-reinforced polymer composite for tribological application. FRP composites have various applications in the automobile, aerospace and marine fields. They are applied to inlet cone, fan exit guide vanes and other parts of structures in a turbofan engine for lightening an engine. The erosion characteristics of the FRP composites are of vital importance due to the operational requirements in dusty environments. In this present work, the impact of stacking sequence on erosion wear behaviour of untreated woven jute and glass fabric-reinforced epoxy hybrid composites has been investigated experimentally. The orientation of glass and jute fabric was kept at (0°–90°) and (45°–45°) for all stacking sequences. All the laminates were prepared using four plies, and, the number and position of glass layers were varied so as to obtain four different stacking sequences. The erosion rate of these composites were evaluated at different impingement angles (30°–90°) at three different impact velocities (V = 48, 70, 82 m/s). Silica sand was used as the erodent. Our results showed that the impingement angle had a significant influence on the erosion rate. The composite materials showed semi-ductile behaviour with the maximum erosion at an impingement angle of 60°. The morphologies of the eroded surface were observed by a scanning electron microscope, and the possible erosion mechanisms were discussed.     

Effect of E-Glass fibre and ply orientation on the mechanical behaviour of FRP composites used for pressure pipe

The main goals of this experimental investigation were to compare the mechanical behaviour of resins reinforced with different woven fabrics (bidirectional and quadriaxial rovings), manufactured with the classical hand lay-up process, and to find the more appropriate industrial pressure pipe. In order to realize such applications, several mechanical properties need to be evaluated. So, a focus was essentially done on the evaluation of the effect of resin and E-Glass fibre ply orientation on the mechanical properties such as tensile strength and flexural strength of the studied composite laminates. An experimental failure analysis was carried out to observe the crack paths and failure mechanisms in the investigated laminate composites. From the main results, it was found that the composites based on R500 fabrics show the best behaviour in tensile while the laminates based on RM fabrics present the best flexural properties. The quadriaxial composite laminates (QA/VE and QA/UP) with stacking sequences of [0°, +45°, 90°, ?45°] present a very ductile tensile behaviour and the highest interlaminar fracture resistance. Consequently, they can be more appropriate for the industrial pressure pipe.     

车削中三维复杂断屑槽刀具断屑仿真研究

为有效缩短现有断屑槽刀具的设计周期、降低设计成本,采用有限元方法模拟了切削过程中切屑折断过程。利用Solid Works软件建立了三种刀具的三维模型,并在Deform 3D软件中对车削45钢工件过程进行了三维切削仿真。其中,工件材料采用了Johnson-Cook模型和Cockroft-Latham韧性断裂准则,仿真模型采用了有效参数设置以保证数值计算精度与效率。通过仿真研究了不同切削参数下的切屑形态、断屑过程及主切削力等。研究结果表明,仿真结果与试验结果吻合良好,该仿真模型及方法能有效应用于断屑槽刀具断屑性能研究,是三维复杂断屑槽刀具设计和切削参数优化的一种新方法。     

Study on vital static properties of fine blanking of GFRP composites with that of conventional drilling

Among the high performance engineering materials, fiber-reinforced plastics play an important role. The present work is concerned with the comparison of vital static strength properties of fine blanking with conventional drilling on hand lay-up made glass fiber-reinforced plastic (GFRP) laminates of four different reinforcement lay-up sequences such as unidirectional [0/0]_n, angle ply [0?±?45]_ns, quasi-isotropic [0/45/90]_ns, and cross-ply [0/90]_n. Observation includes tensile and flexural bending strengths of the specimens without hole and with hole by conventional drilling and fine blanking. In this work, an endeavor has been made to simulate the service conditions to determine their effect on the response of composite laminates. Detailed studies on GFRP composites when subjected to different loading environments such as static loading, particularly tensile loading, and low frequency high amplitude (fatigue) loading were carried out. The response of the composite laminates to these service environments has been evaluated in terms of flexural strength and modulus. From the tensile study, it was observed that by inserting a hole at center by drilling, the strength was reduced to one third, and by inserting a hole at center by fine blanking, the strength was increased nearly 20% than that of drilling. Apart from this, the flexural test conducted on polymeric composite specimens showed that an exposure to low frequency and high amplitude loading enhances the flexural strength up to certain duration of exposure, beyond which, due to accumulation of damage within the composites, the flexural strength reduces with number of cycles. This can be attributed to possible strain-induced stiffening of fibers and interface.     

智能焊接机器人的机构设计与仿真

用SolidWorks软件建立了焊接机器人的三维实体模型和虚拟样机模型,并在SolidWorks平台下,用Solid Works Simulation实现静力学仿真,仿真得出结构的应力、位移、应变情况;用SolidWorks Motion实现机器人的运动学仿真,得出机器人各关节运动的角位移、角速度、角加速度曲线。最后对仿真的结果进行分析,为焊接机器人的机构设计提供数值依据,以更好地改进机器人的机构设计。     

Design of Roller Beams Using SolidWorks Software

Russian Engineering Research - Roller beams are investigated by the finite-element method, using SolidWorks Simulation software. Static analysis of the beam’s stress–strain state...