钢索受力动力检测理论与试验研究-土木工程专业论文.docxVIP

摘要 摘要 钢索作为～种高效地承受拉力的构件，在工程结构中已大量使用。为了在 施工和结构监测的过程中准确获得钢索的内力，出现了许多索力测试方法，其 中振动法是被广泛使用的方法之一。振动法是根据钢索所受的拉力与其自振频 率之间的关系，由实测的自振频率值间接推算出索力的方法。 本文针对振动法主要进行以下研究： 阐述了本文的研究背景及意义，综合国内外研究成果，总结了多种索力测 量方法，分析了使用振动法测量索力的优势及尚存的不足之处。 系统综述了索的自由振动的基本理论，并从基本理论出发分析了索的垂度、 抗弯刚度、边界条件、附加集中质量等因素对索的振动的影响。 提出一组索力计算豹简化公式，及通过频率识别索的刚度和边界的方法， 通过算例验证了此方法对于备类索尤其是刚性索的索力测量可得到较好的结 果。讨论了本文索力简化计算方法的误差敏感性，并提出减小误差影响的建议。 通过试验验证7本文提出的索力简化计算方法的有效性和实用性。 关键词：索力，频率，振动法，参数识剐  Abstraet ABSTRACT cable，one of the components which can effectively bear the tensile force，has been widely used in structures，Many methods have been proposed to measure the cable tension during structural construction and detection process，and vibration method iS one of the universally used methodS．Based on the relationship between tension and frequencies of the cable，vibration method Can estimate the cable tension indirectly throu曲the natural frequencies． The work presented in this paper focuses on several following aspects． The research backwood and significance ofthis paper are expounded．Based on the reviewing and summarizing the existing study achievements and comparing different methods on cable tension measurement,the advantages and problems of vibration method arc indicated． The principle of cable linear vibration is presented．And based on the principle， the influence of sag，flexural rigidity,boundary condition and lumped mass on the natural frequencies ale discussed． Practical formulas considering flexural rigidity of cable are deduced，and a method to identify the flexural r主gidjty and boundary use of natural frequencies is proposed．Case study proves that the method is correct and practical for various cables，especially suitable for inflexible cable．The sensitivity of this method to frequencies errors is studied and some advice for reducing the sensitivit)r is given． A dynamic test is conducted to validate the practical formulas and the method of identi母ing the flexural rigidity and boundary． Key Words：cable tension，frequency,vibra