Research On Optimization Of Noise Of A Rough Terrain Crane Under Idle Condition

In modern construction,construction cranes play a very important role.Customers pay more and more attention to the vibration and noise of products in addition to considering the lifting performance and safety performance of crane products,which has become an important factor affecting customers’ choice of products.Studying the NVH characteristics of construction cranes,reducing the noise in the construction crane driving cab,and providing users with a comfortable driving experience are the inevitable development requirements for construction crane manufacturers to improve their product competitiveness.In this paper,the passenger vehicle NVH research method is applied to the engineering crane under the background of the NVH performance improvement project of the control room of a rough terrain crane,and stablished a complete set of design methods for noise reduction of the control room of the engineering crane.The research is carried out from the aspects of finite element model establishment,modal test,idle road test,contribution of transfer function path and grid participation of crane control room.The topology optimization design is carried out on the related structure of the control room body,the right ear sound in the frequency range of 35-45 Hz under idle condition is optimized,and the NVH performance of this rough terrain crane is improved.The main contents of this topic include:(1)Firstly,using HyperWorks build the finite element model of the rough terrain crane control room body in white,the modal simulation and modal test experiments were compared with the vibration shape and frequency to verify the accuracy of the finite element model,also understand the dynamic characteristics of the body structure of the control room.(2)Secondly,the TB model of the control room,the sound cavity model of the control room and the sound cavity model of the seat were established.The acoustic cavity modes of the control room were analyzed based on the acoustic-structure interaction theory.The analysis showed that the sound pressure distribution in the control room was reasonable,and the acoustic-structure interaction model of the control room was established,which laid a foundation for the subsequent transfer function analysis and noise response analysis.(3)the noise transfer function analysis was carried out on the control room,and the crane idle road test,record the corresponding connecting point of the vehicle body signal.Take the processing signal as the excitation load to calculate the frequency response analysis.Compare the analytical data with the measured spectrum curve to verify the simulation model is reliable.(4)Finally,a broadband topology optimization method is proposed to optimize the noise response in the frequency range.Based on the TPA method,the contribution of each transfer path function and force in the control room was analyzed to identify the main path of noise transfer function,and then the grid participation of the path was analyzed to find the largest contribution region.The structure optimization of body panel in this region was carried out by broadband topology optimization method.Finally,improves the NVH performance of the rough terrain crane.The final simulation results show that the interior noise in the regional frequency range is improved.