Finite Element Analysis on a Square Canister Piezoelectric Energy Harvester in Asphalt Pavement

A novel square canister piezoelectric energy harvester was proposed for harvesting energy from asphalt pavement. The square of the harvester was of great advantage to compose the harvester array for harvesting energy from the asphalt pavement in a large scale. The open circuit voltage of the harvester was obtained by the piezoelectric constant d33 of the piezoelectric ceramic. The harvester is different from the cymbal harvester which works by the piezoelectric constant d31. The finite element model of the single harvester was constructed. The open circuit voltage increased with increase of the outer load. The finite element model of the single harvester buried in the asphalt pavement was built. The open circuit voltage, the deformation difference percent and the stress of the ceramic of the harvester were obtained with different buried depth. The open circuit voltage decreased when the buried depth was increased. The proper buried depth of the harvester should be selected as 30 - 50 mm. The effects of structure parameters on the open circuit voltage were gotten. The output voltage about 64.442 V could be obtained from a single harvester buried under 40 mm pavement at the vehicle load of 0.7 MPa. 0.047 mJ electric energy could be gotten in the harvester. The output power was about 0.705 mW at 15 Hz vehicle load frequency.

A distributed pavement monitoring system based on Internet of Things

Pavement is an important part of transportation infrastructure.In order to maintain pavement before the damage and improve the service quality,it is necessary to develop an intelligent and durable pavement information monitoring system.However,the pavement dynamic response monitoring is highly costly,easily obsolete and statistically redundant.The emergence of the Internet of Things(IoT)technology promises to change that.In this paper,an architecture of a distributed road IoT monitoring system is proposed,which has an acquisition layer,a preprocessing layer,a processing layer,an interaction layer,an energy layer and a network layer.Then,a prototype wireless pavement vibration monitoring system based on the IoT is developed,which consists of a number of wireless sensing nodes,a gateway,a remote server and a browser.Finally,data preprocessing,wireless communication,time synchronization,data processing and visualization,which represent the key to an effective system,are tested and discussed.The prototype wireless pavement vibration monitoring system provides a viable scheme for upgrading the IoT system and its application in the road infrastructures.In the future,any smart road will have an IoT wireless monitoring system to monitor the traffic,environment,and pavement information,which help enable traffic guidance,signal control,danger warning,scientific maintenance decision-making.