在役流动式起重机臂架风险与寿命评估及可修复性决策

发布时间：2018-01-21 00:39

  本文关键词： 在役流动式起重机 臂架结构 潜在失效模式 风险评估 疲劳剩余寿命评估 可修复性评估与决策　出处：《太原科技大学》2017年博士论文　论文类型：学位论文

【摘要】：流动式起重机作为现代物料搬运的特种设备,广泛应用于建筑、冶金、造船、电力、石化、能源等领域。臂架结构作为流动式起重机的主要承载结构件,其结构复杂、服役条件苛刻且易损伤失效,是工程机械中附加值较高、量大面广的共性关键部件。如何有效可靠地评价在役流动式起重机臂架结构的现役性能、安全状态、剩余寿命,以确保臂架结构修复的最佳准入期,延长其使用寿命,使其材料利用率最大化,实现节能减排的效果是制造企业、用户、特种设备监管部门共同关心的问题。迄今为止,在役流动式起重机臂架结构风险评估、寿命评估和可修复性评估与决策尚无相关方法和标准可依。对于如何判定延用、修复、更换、报废缺乏方法和标准的支撑。针对上述问题,本文主要开展了如下研究工作:1)为有效预测在役流动式起重机臂架结构的潜在失效模式,构建基于实例推理的臂架结构潜在失效模式预测模型。通过调研、收集流动式起重机臂架结构有限失效模式历史信息,建立流动式起重机臂架结构失效模式模糊数据库,在机型匹配的条件下,构建与待评估起重机同机型、不同典型使用工况的失效模式实例库,结合实例推理技术,预测待评估起重机臂架结构的潜在失效模式,利用流动式起重机臂架结构参数化有限元模型和仿真计算平台,修正潜在失效模式,为后续风险评估、疲劳剩余寿命评估提供基础性信息及数据。2)针对多重耦合失效模式下在役流动式起重机臂架结构安全性问题,提出基于潜在失效模式的臂架结构风险评估方法。以在役流动式起重机臂架结构潜在失效模式为基础,采用改进DEMATEL法,建立臂架结构危险点及其各级评价指标间的直接、间接影响模糊关系矩阵,推导各级指标的影响度矩阵与被影响度矩阵,得到各级评价指标的中心度和原因度,分析评价指标间的关联性与影响性,根据关联度与影响度分配权重,结合模糊综合评价理论,量化臂架结构的失效风险,实现多重耦合失效模式下在役流动式起重机臂架结构的风险评估。3)针对流动式起重机工作载荷在时空上间歇、循环的随机性,导致实测载荷的随机性以及试验条件的局限性,使得大规模载荷谱试验难以实施的问题,提出基于数理统计技术的随机载荷谱获取方法和基于人工智能预测技术的当量载荷谱预测方法。通过采集、统计、记录特定时段内不同特征参数下起重机的工作循环次数簇,形成小样本的实测载荷谱,利用数理统计技术(按常用的6种概率分布模型对起重量样本进行分布拟合,应用AIC信息准则对概率分布模型进行评价,给出起重量样本的最佳概率分布模型)与拉丁超立方抽样相结合或新型智能优化算法的人工智能预测技术,获取定检周期内的随机或当量起重量样本,根据流动式起重机额定起重量表、起升高度曲线和额定起重力矩表,确定对应起重量的臂架工作长度、工作幅度,刻画符合工程实际的随机特征参数和与之一一对应的工作循环次数,得到定检周期内的随机载荷谱或当量载荷谱,为疲劳剩余寿命评估提供基础性数据。4)针对在役流动式起重机服役过程面临多失效模式耦合,导致其臂架结构安全性难以确定的问题,提出基于工作循环载荷动力效应及多失效模式耦合的流动式起重机臂架结构疲劳剩余寿命评估方法。以获取的随机或当量载荷谱为基础,根据流动式起重机工作循环过程,建立考虑工作循环载荷动力效应的臂架结构危险点处第一主应力-时间历程理论仿真模型,模拟再现检测周期内流动式起重机工作循环过程中臂架结构危险点处第一主应力的时间历程,利用雨流计数法,提取对应危险点的双参应力谱,结合损伤容限设计及断裂力学理论,构建基于随机或当量载荷谱的疲劳剩余寿命评估模型,估算单一及耦合失效模式下臂架结构对应危险点处的疲劳剩余寿命,为损伤臂架结构可修复性评估与决策提供门槛条件。5)针对在役流动式起重机损伤臂架结构的延用/修复/更换/报废问题,从结构现役性能可利用性、修复技术可行性、经济可行性、环境资源可行性的维度,建立损伤臂架结构可修复性综合评估与决策模型。对于具有疲劳剩余寿命(修复准入期)的各损伤臂节截面拉应力区域(压应力区域)的危险点,分析其检测周期节点处的可靠性(危险点的强度冗余性),联合可靠性阈值(最小强度冗余因子),确定危险点处现役性能的可利用性,根据修复工艺过程,量化技术可行性评价指标,评价修复技术的可行性,以企业特定时段内流动式起重机损伤臂架结构的修复总费用为基础,采用作业成本法,追溯不同失效特征对应损伤臂节的修复成本,形成修复成本数据库,利用改进相关向量机,预测与待评估流动式起重机各损伤臂节失效特征对应的修复成本,结合购置新品臂架结构所需费用,评价损伤臂架结构修复的经济性,判断臂架结构修复的环境资源效益,给出损伤臂架结构可修复性的综合决策结果,为报废及相关标准的制定提供重要的理论依据。6)为便于工程应用,基于VC++6.0/C#平台,将以上理论和方法集成,开发“流动式起重机臂架结构风险与寿命评估及可修复性决策系统”,为在役流动式起重机臂架结构潜在失效模式预测、风险评估、载荷谱预测、疲劳剩余寿命估算、可修复性综合评估与决策提供软件技术支持。
[Abstract]:The mobile crane as a special equipment of modern material handling, widely used in building, metallurgy, shipbuilding, electric power, petrochemical, energy and other fields. The mobile crane jib structure as the main bearing structure, its structure is complex, harsh conditions and easy to damage and failure is high value-added service, engineering machinery, common key components a large amount of wide. How to effectively and reliably evaluate the performance in active service, the mobile crane jib structure of the safety state of residual life, to ensure the best access period of boom structure repair, prolong the service life, the material utilization is maximized, achieve the effect of energy saving and emission reduction is a manufacturing enterprise, the user. Common concern of special equipment supervision department. So far, the risk structure of existing mobile crane arm frame evaluation, life assessment and maintainability evaluation and decision method and standard. Shang Wuxiang closed on On how to determine the use, repair, replacement, scrap the lack of methods and standards support. To solve the above problems, this paper carried out research work as follows: 1) for predicting the potential in the service mode of mobile crane boom structure failure, construction of CBR arm structure prediction model based on potential failure mode. Through research. Collect the mobile crane jib structure finite failure mode of historical information, establish the mobile crane boom structure failure mode in fuzzy database, models, conditions, construction and evaluation for the same type of crane, the failure mode of different working conditions of the typical case base, combined with case-based reasoning technology to evaluate the potential prediction model of crane jib structure the failure of the mobile crane with jib structure parametric finite element model and simulation platform, correction of potential failure mode for the subsequent risk assessment, The remaining fatigue life provides the basic information and data.2 assessment) for multiple failure mode coupling in existing mobile crane boom structure security assessment method of jib structure risk potential failure mode is proposed. The existing mobile crane boom structure potential failure mode based on improved DEMATEL method, set up the arm frame structure and its risk evaluation at all levels between direct and indirect effects of the fuzzy relation matrix, affect the derived indicators at all levels of the matrix and influence matrix, at all levels of evaluation index centrality and causes analysis, relevance and impact evaluation index, according to the correlation degree and influencing degree of weight distribution, combined with the the theory of fuzzy comprehensive evaluation, the failure risk of the boom structure, realize the coupling multiple failure modes in the risk assessment of existing mobile crane boom structure for mobile.3) Crane work load in time and space, intermittent, random cycle, resulting in limitation of measured load randomness and test conditions, the test load spectrum is difficult to implement large-scale problems, put forward random load spectrum acquisition method of mathematical statistics and prediction method of equivalent load forecasting technology based on artificial intelligence. By collecting the spectrum, statistics, records within a particular time period of different characteristic parameters of crane operation cycles of clusters, forming small samples of measured load spectrum, using statistical techniques (according to 6 kinds of commonly used to sample weight distribution fitting, probability distribution model and application of AIC information criteria for evaluation of the probability distribution model gives the best probability distribution model the weight of the sample) and Latin hypercube sampling combined with artificial intelligence or intelligent optimization prediction technology, obtain periodic inspection in random Or the equivalent weight of the sample, according to the mobile crane rating table, lifting height curve and rated load moment, determine the corresponding arm working length, the weight of the working range, describe the stochastic parameters in accordance with engineering practice and corresponding work cycles, get the random load periodic inspection the spectrum or equivalent load spectrum, fatigue life assessment to provide the basic data for.4) in the service of mobile crane service faces many failure modes coupling, the safety of arm frame structure is difficult to determine, a job evaluation method based on cyclic loading dynamic effect and multiple failure modes coupled flow frame the structure of the crane arm fatigue residual life. In order to obtain the random or equivalent load spectrum as the basis, according to the process of the mobile crane work cycle, considering the dynamic effect of cyclic loading The jib structure of dangerous point of the first principal stress time history simulation model, simulation of flow detection cycle time history of jib structure of dangerous point process crane work cycle in the first principal stress, the rain flow counting method, the extraction of the dangerous point corresponding to two parameter stress spectrum with damage tolerance the design and the theory of fracture mechanics, evaluation model of random fatigue life or equivalent load spectrum based on the estimation of the remaining fatigue life of single and coupled failure risk of jib structure corresponding to mode, damage to the jib structure repair assessment and decision-making threshold condition.5) in battle of mobile crane arm injury frame use / repair / replace / scrap, from the existing performance availability, feasibility, repair technical and economic feasibility of environmental resources, the feasibility of the establishment of jib structure dimension, damage repair The complex of comprehensive evaluation and decision making model. With the remaining fatigue life (access repair period) the injury of brachial sections of tensile stress area (compressive stress) risk, reliability analysis of its detection nodes (strength redundancy of the dangerous point), combined with the reliability threshold (the minimum strength redundancy factor) sure, the dangerous point of service performance can be used, according to the repair process, the feasibility of quantitative evaluation index, feasibility evaluation of repair technology, with the enterprise specific time period flow repair total cost of crane jib structure damage based on the activity-based costing, repair cost tracing different failure characteristics corresponding to damage the boom the cost of repair, the formation of the database, using the improved relevance vector machine, prediction and assessment for the repair cost of mobile crane arm joint failure characteristics corresponding to different damage, combined with the purchase of new jib structure The expenses needed for the economic evaluation of damage repair of jib structure, environmental resources effectiveness judgment of jib structure repair, given the damage of jib structure may be the result of comprehensive remediation decisions, provide an important theoretical basis for the formulation of.6 for scrap and related standards) for the convenience of engineering application, based on the VC++6.0/C# platform, the above theory and method integrated assessment of mobile crane boom structure risk and life development "and repair decision system" for the risk assessment of existing mobile crane boom structure prediction, potential failure mode, load spectrum prediction, fatigue residual life estimation, maintainability comprehensive evaluation and decision making to provide software technical support.

【学位授予单位】：太原科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TH21
，

本文编号：1449920