压电式复合路面能量收集效率的协同增强方法

Piezoelectric based energy harvesting technology is a requirement of developing smart pavement. The results of last NSFC program of the applicant show that the energy harvesting efficiency will be reduced by the stiffness difference between asphalt mixture and piezoelectric generator. The method to improve the performance is developing an energy harvesting oriented composite pavement structure, which is comprise of piezoelectric generator, concrete slab and thin asphalt layer. The theoretical analysis, 3D finite element analysis and multiple scale tests will be adopted in this research. The pattern of energy in composite pavement caused by the moving vehicle will be analyzed. The mechanism of how the energy harvesting efficiency is influenced by the factors will be explored, such as the stiffness difference between pavement and piezoelectric transducer, the conflict of stress required by energy harvesting and the limit of piezoelectric transducer, and the frequency difference between pavement and piezoelectric transducer. The methods to improve the energy harvesting efficiency will be developed by amplified stress and harmonic vibration. A prototype of composite pavement structure with energy harvesting function will be constructed in the laboratory. After performance testing and evaluation, all the technologies developed in this project will be optimized. The results will improve the energy harvesting efficiency from pavement. They are important supporting for green energy hunting and smart pavement developing.

压电式路面能量收集技术是智能道路的重要支持手段。申请人依托青年自然科学基金项目的研究表明，在沥青路面能量收集技术中，受沥青混合料与压电材料刚度差过大等因素的约束，实际能量收集效率远低于预期。为此，本项目提出由“压电器件-混凝土板-沥青层”组成的复合路面结构，为路面能量收集效率提升提供基础；拟采用理论分析、多尺度实验和精细化数值模拟等手段，掌握车辆激励下复合路面的能量表现形态及其收集机理；揭示压电式复合路面中器件与路面的模量差异、器件与路面的振频不同等因素对能量收集效率的约束机制；融合刚度匹配、应力平衡、振频协调和性能优化等思想，提出压电器件的能量收集效率协同增强方法；在结构试槽内修筑压电式复合路面原型结构，足尺验证其能量收集效率和路用性能，在此基础上进一步优化压电式复合路面的器件、结构与参数。研究成果将提升压电式路面的能量收集效率，为智能路面和路域能量收集提供理论基础和技术支持。

压电式路面能量采集技术为功能道路和智能道路提供了新的供能路线。首先，本项目提出了新型的压电式复合路面结构，并且基于水泥混凝土路面的力学响应和振动特性测试，建立了用于动态响应与振动模态分析的路面结构三维有限元分析精细模型；进而探讨了压电器件可采集的机械能总量及衰减规律、时空分布规律，为后续压电器件结构选型、设计和布设提供依据。其次，采用理论分析、多尺度实验和数值模拟方法明确了压电能量采集效率的影响机制和典型应力放大结构的受力特性，揭示了压电器件及阵列的应力与效能之间的矛盾；进而采用影响曲面法和正交设计分析了结构和材料参数对压电器件及阵列的电学和力学性能的影响规律。结果表明，压电器件在匹配阻抗下的输出功率达到11 mW，且能够承受路面内部极限应力状态；压电装置在匹配阻抗下的输出效率达到84 mW，且能量输出与荷载水平和加载频率变化正相关。再次，采用铺面振动理论获取了复合路面的振动特征，采用数值模型求解了叠柱式应力放大结构低阶固有频率和振型，并且采用正交设计确定了面向谐振的叠堆式结构最优参数组合；进而提出了面向器件和路面振动频率协调的器件结构设计方法。结果表明，在给定激振频率和路面振动主频的条件下，可以通过调整谐振器支撑弹簧和上部质量块质量，实现压电器件及阵列的效能放大。最后，提出了压电装置与复合路面的装配化集成方式，同时采用数值模拟方法探究了路面结构、荷载特征、埋设参数对压电式复合路面能量收集效率的影响；进而通过足尺试验验证并分析了压电式复合路面的能量采集效率和路用性能。研究成果可提升压电式路面的能量收集效率，为路面机械能收集提供理论基础和技术支持。