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平行压下辊式板材矫直机参数分析 总被引:2,自引:0,他引:2
根据弹塑性弯曲理论,给出了辊式矫直机压下量与反弯曲率的数学模型,从而计算了平行压下辊式矫直机矫直过程中的残余曲率分布,确定了给定精度要求所需的最小辊数。 相似文献
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对于拉伸矫直机,带钢在矫直机辊子上的曲率半径的计算尤为重要,只有确定了该曲率半径,才能进一步计算带钢的反弯曲率、弹复曲率和残留曲率,进一步计算带钢的平直度。假定带钢在矫直辊上的曲线为抛物线,给出带钢反弯曲率半径的计算方法,并且进一步讨论矫直辊辊子直径的计算方法。 相似文献
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针对变辊距矫直机具有不同于恒辊距矫直机的结构特点 ,给出变辊距型钢矫直机辊数、辊距的确定方法 ,并计算出各辊的弯曲力矩及矫直力 ,最后求得设备电机功率。通过设备的具体运行证明 ,变辊距结构对改善设备的受力状况及提高型钢矫直质量十分有利 相似文献
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辊式矫直机的矫直质量和设备状态由其矫直能力所决定.针对热轧高强钢来料强度高、板形差的特点,详细分析了限制矫直机能力的主要因素,并通过具体计算公式明确了弯曲曲率比、矫直机辊径、许用矫直力、单辊许用矫直扭矩、传动电动机额定功率等因素对矫直能力的影响.结合实际生产应用,分析了矫直机力能参数与钢板的弯曲曲率比、厚度和屈服强度之间的对应关系;绘制了不同弯曲曲率比下的矫直能力曲线,针对来料板形较差的热轧高强钢板,在矫直能力范围内尽可能采用较大的弯曲曲率比进行矫直,进一步提高了其矫直效果. 相似文献
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板形是带钢质量的重要判定指标,常见的板形缺陷有边浪、中浪、1/4浪等,其实质是残余应力在带宽上的分布不均。拉伸弯曲矫直机通过张力辊组、弯曲辊组和较真辊组的共同作用,使带钢在低于屈服强度的张力作用下发生塑性延伸,从而有效消除浪形缺陷,改善板形,提高带钢质量。然而在拉伸弯曲矫直机的设计和使用过程中,对拉伸弯曲矫直机参数的调整多基于经验,缺少理论指导。为了定量分析拉伸弯曲矫直机参数对浪形缺陷的改善效果,使拉伸弯曲矫直机在实际生产中发挥更好的作用,以某1 450 mm带钢酸洗冷轧生产线上的拉伸弯曲矫直机为研究对象,使用有限元软件ANSYS/LS-DYNA基于三维弹塑性有限元法建立了拉伸弯曲矫直机模型,对拉伸弯曲矫直机矫直过程进行了模拟,分析了张力和插入深度对初始浪形分别为边浪和中浪的带钢矫直后板形的影响规律。结果表明,经过拉伸弯曲矫直的带钢浪形缺陷得到显著改善;插入深度和张力对初始浪形缺陷分别为边浪和中浪的带钢板形的影响规律一致;3个辊组中矫直辊组的插入深度是影响带钢板形的主要因素,随着矫直辊组插入深度增大,带钢矫直后板形由边浪转变为平直,且随着矫直辊插入深度进一步增大,板形又由平直转变为边浪;随着入口张力增大,带钢矫直后板形由边浪转变为中浪。 相似文献
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辊式矫直机的矫直功能是中厚板生产线上保证板带板形的重要手段,其矫直过程可以消除或均匀板带内部残余应力,对提高板带综合质量具有重要意义。为了分析矫直机对带有边浪的板带的矫直过程以及矫直效果,首先建立了板带弯曲挠度的计算模型,为确定矫直辊的压弯量奠定了基础。在矫直模型作为压弯量设定的基础上,参考现场实际设备尺寸,通过借助大型商用有限元软件ANSYS建立了11辊的辊式矫直机有限元仿真模型,并针对研究目标设计了相应的仿真工况,将模型的矫直过程调整为采用上辊系整体压下倾斜的设置,对不同浪高的板带进行仿真分析。将有限元模型计算出的矫直力与生产实际设备的矫直力进行对比,有限元模型的矫直力计算偏差约为8.3%,满足计算精度要求。设置边浪浪高分别为5、10、20 mm的板带作为仿真工况,对其矫直过程进行仿真计算,提取仿真结果中的相关数据进行分析,发现在不采用弯辊的条件下,矫直过程同样具有消除板带不平度的作用。结果表明,在浪高较大时,矫直过程消除不平度的作用明显,但是矫直后板带并不能达到最终的平整度要求;在浪高较小时,矫直过程对不平度的消除能力较弱,但矫直后板带不平度可以达到最终的平整度要求。在分析的基础上,在工业现场的实际设备中进行相关试验,试验数据表明,仿真结果与试验结果趋势相同。 相似文献
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为了摸清棒材斜辊矫直过程中各曲率的变化规律,应用小曲率平面弯曲弹复理论以及棒材弯曲弹复的曲率方程式,实现棒材一次反弯弹复的计算模型,基于棒材每旋转半周反弯一次的规律以及上一次弹复后的残余曲率认为是下一次弯曲的原始曲率,建立棒材全流程二辊矫直过程弯曲弹复模型,获得整个矫直过程中原始曲率、弯曲曲率、弹复曲率以及残余曲率的演变过程,得到棒材最终的残余曲率.应用该理论模型对现场生产过程进行了计算,与现场结果一致,验证了理论模型的正确性.应用所建立的理论模型对不同直径、不同材料屈服强度、不同原始挠度的棒材矫直过程分别进行分析,获得了不同来料参数情况下矫直过程的变形规律.该模型可以为二辊矫直机辊型优化设计与工艺参数计算提供理论依据. 相似文献
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《钢铁研究学报(英文版)》2016,(12):1268-1276
A mathematical model of friction coefficient was proposed for the roll force calculation of hot-rolled strips. The online numerical solving method of the roll force calculation formula based on the proposed friction model was developed and illustrated by the practical calculation case.Then,the friction coefficient during hot strip rolling was estimated from the measured roll force by force model inversion.And then,the expression of friction model was pro-posed by analyzing the calculation process of stress state coefficient,and the model parameters were determined by the shared parameter multi-model nonlinear optimization method.Finally,the industrial experiments demonstrated the feasibility and effectiveness of the related models.The accuracy of the new roll force model based on the built friction model was much higher than that of the traditional Sims model,and it could be applied in the online hot roll-ing process control. 相似文献
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对宽厚不锈钢复合板层间真空热轧制变形过程进行受力分析,将热轧变形区分成I、II两个区间,运用主应力法建立各个区间的力平衡方程,根据边界条件和屈服准则求出各变形区的长度和各变形区所受压力,建立轧制力计算数学模型,在此基础上分析轧制工艺参数对宽厚不锈钢复合板轧制区间内不同应力分布的影响规律。将实际参数代入轧制模型计算公式,应用Matlab编程求得理论计算值,并与实测值进行比较。研究结果表明:轧制力模型可用于预测轧制力的大小,满足工程要求,轧制复合过程研究有助于优化成形工艺、预测产品性能,为今后此类材料的研究开发提供了参考依据。 相似文献
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Mostafa Balali Mohamad Bagher Limouei Mojtaba Balali 《Transactions of the Indian Institute of Metals》2018,71(3):605-616
During last decades, severe plastic deformation (SPD) techniques have developed and increased their applications in variety of industries such as aerospace, nuclear, automotive, marine etc. One of emerging SPD process is simple shear extrusion (SSE). In the present study, an attempt was made to optimize parameters affecting SSE process of pure copper namely maximum distortion angle, channel length and ram speed on effective plastic strain and maximum punch force. Firstly, the process was numerically simulated by use of ABAQUS software. Then, the developed finite element model was verified by confirmatory experiment taking into account the punch force. 15 series of simulation runs were implemented incorporating three aforementioned factors within three levels. Then, response surface methodology was used here to correlate relationship between process parameters to forming force and effective strains. Sensitivity analysis was also carried out to find which factor had greatest impact on process quality characteristics. In order to find optimal parameter setting for maximum strain and strain rate as well as minimum punch force, desirability approach was utilized. Results revealed that distortion angle was the most significant factors affecting plastic strain and punch force, while the ram speed had greatest impact on strain rate. The specimens at optimum parameters (i.e. 45° distortion angle, 90 mm channel length and 0.3 mm/s ram speed that resulted in maximum plastic strain) were processed by SSE and mechanical properties and microstructure analysis were studied. It was found from the results that microstructure of the samples were significantly refined by performing SSE at optimum level that resulted in improvement of samples strength and hardness. 相似文献
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To explain observed differences in the activation dependence of force redevelopment kinetics between cardiac and skeletal muscle, two numerical models of contractile regulation by Ca2+ were investigated. Ca2+ binding and force production were each modelled as two-state processes with forward and reverse rate constants taken from the literature. The first model incorporates four possible thin-filament states. In the second model Ca2+ is assumed not to dissociate from a thin-filament unit in the force-generating state, resulting in three states. The four-state model can account for the activation dependence of the rate constant of tension redevelopment (ktr) seen in skeletal muscle, without requiring that Ca2+ directly modulates the kinetics of any step in the cross-bridge cycle. Using identical kinetic parameters, the three-state model shows no activation dependence of ktr, consistent with our results in cardiac muscle. Following a step increase in [Ca2+], the rate of rise in tension (as described by the rate constant kCa) varies with the final [Ca2+] for both models, consistent with experimental results from skeletal and cardiac muscle. These numerical models demonstrate that experimental measurements thought to reveal changes in kinetic parameters may simply reflect coupling between the two kinetic processes of Ca2+ binding and force generation. Furthermore, the models present possible differences in the Ca2+ activation scheme between cardiac and skeletal muscle which can account for the contrasting activation dependencies of force redevelopment kinetics. 相似文献
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Abstract: In the hot strip rolling control system, the temperature distribution and deformation resistance are the main parameters affecting prediction of rolling force. In order to improve the model prediction precision, an optimiza- tion algorithm based on objective function was put forward, in which the penalty function index was adopted. During the adaptation process, the temperature distribution and deformation resistance were taken as the optimized parame ters, and the Nelder-Mead simplex algorithm was used to search the optimal solution of the objective function. Fur thermore, the temperature adaptation and force adaptation were solved simultaneously. Application results show that the method can improve the accuracy of the rolling force model obviously, and it can meet the demand of the indus trial production and has a good application prospect. 相似文献
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利用有限元分析软件ANSYS对轧机承载辊缝变形的仿真,分析轧机轧制力、弯辊力及工作辊窜辊对承载辊缝的凸度影响程度,结合现场机架间带钢的浪形,优化二级板形模型设定参数,实现轧机稳定轧制。实践证明,人工修正轧机负荷分配以及CVC轧辊位置,可更好地控制前机架比例凸度,满足后机架间平直度目标的要求,从而提高板凸度的命中率及轧机轧制的稳定性。 相似文献