As a new type of inorganic green and high performance fiber material, basalt fiber has broad application prospects in the field of offshore wind power. In order to promote the application of basalt fiber in offshore wind turbine blade, the static tensile test and tensile-tensile fatigue test of basalt fiber reinforced polymer (BFRP) at different stress levels were carried out to obtain the elastic modulus, tensile strength, and S-N curve of BFRP. The equivalent model of basalt fiber bionic plate and the finite element model of wind turbine blade were established by Ansys Workbench software. Based on nCode software, the fatigue performance of the offshore wind turbine blade with basalt fiber bionic plate was analyzed and its fatigue life was predicted. The results show that the elastic modulus of BFRP is more than 2.5 times that of glass fiber reinforced polymer (GFRP), and BFRP has good plastic energy dissipation capacity. The equivalent model based on equivalent plate theory is suitable for static and dynamic analysis of basalt fiber bionic plate. The fatigue damage of the wind turbine blade under low wind speed is mainly concentrated in the edge of the blade root, the area where the skin and the web intersect and near the tip of the blade. Under the high wind speed, the fatigue damage covered the whole skin, only slight damage occurred at the trailing edge of the tip. The dangerous point is mainly located near the tip of 50 m-60 m along the span direction. The traditional Miner theory can accurately predict the fatigue life of wind turbine blade, and the fatigue life of the wind turbine blade with basalt fiber bionic plate is 29 years, while the fatigue life of the glass fiber wind turbine blade at the same scale is less than 1 year.
The grouted connection (GC) of the offshore wind turbine (OWT) jacket foundation mainly bears axial loads, the wind and wave load in the working environment make the structure prone to fatigue problems. The construction environment of the OWT foundation is relatively harsh, so there will be vertical and horizontal errors during the construction process. In this paper, the fatigue test of 9 specimens were designed to analyze the influence of vertical and horizontal errors, water ingression and other factors on the axial fatigue performance of the GC section. The static ultimate bearing capacity test was carried out to determine the load ranges of the fatigue test. Results of fatigue tests indicate that the fatigue performance of the GC considerably degenerates with the load eccentricity, especially at the end sections of the inner and outer tubes. Water ingression has a significant negative influence on the fatigue performance of the GC section. The presence of water contributes to the propagation and development of cracks in the grout layer. Load range, vertical and horizontal errors and grout material have negligible effect on the fatigue performance of the structure.
聚氨酯材料具有轻质价廉、变形能力强等优点,为探究填充聚氨酯材料对薄壁铝合金管轴压性能的影响,完成了15组聚氨酯铝合金复合薄壁管的轴压试验.试验结果表明,此类复合构件在轴向压力的作用下普遍呈现端部局部失稳的破坏模式,填充密度为50 kg/m3、100 kg/m3的聚氨酯没有明显提升铝合金薄壁圆管的承载力和刚度.随后采用数值模型研究了径厚比、长细比等因素对聚氨酯铝合金复合薄壁圆管轴压承载性能的影响规律.最后基于Donnell方程和Ramberg-Osgood模型,拟合得到聚氨酯铝合金复合薄壁圆管承载力计算式,计算式的计算结果和试验及数值计算结果的对比表明,该计算式具有足够的准确性.
介绍了消能减震技术在某既有公共建筑改造设计中的应用.该建筑为建于2011年的多层现浇混凝土框架结构.由于建筑功能改变,抗震设防类别由丙类调整为乙类,相应抗震等级由三级提升为二级,拟采用设置黏滞阻尼器(墙)的消能减震设计.通过基于复模态反应谱法的等效弹性迭代计算和小震弹性时程分析,黏滞阻尼器(墙)工作状态良好,可有效发挥其耗能作用,可为主体结构提供5%左右的附加阻尼比.运用SAUSAGE软件对结构进行多遇、设防、罕遇地震下的时程分析及结构损伤评定,论证了设置消能减震构件的有效性及结构抗震安全性.结构在罕遇地震下的层间位移角为1/122,塑性发展水平较低,结构的抗震等级和抗震构造措施要求可仍按三级设计,综合考虑建筑外立面及室内装修的较少破坏,建筑的总体造价降低.
基于对某高校建筑外墙饰面层构造探查以及完损状况检测结果,分析外墙饰面层的损伤率及其典型特征:建筑外墙饰面层出现的损伤大多为粘结性损伤,其中空鼓、脱落现象较多;建筑服役时间越久,其外墙饰面层损伤状况相对越严重;东、南、西朝向的外墙饰面层易受环境影响,损伤率较高;涂料构造饰面层做法损伤较轻.采用数据分析手段开展外墙饰面层损伤特征分析,可为建筑外墙检测与运维提供参考借鉴.
