Static And Dynamic Characteristics Analysis And Kinematics Simulation Of Tire-type Cement Pavement Demolition Vehicle

With the acceleration of urbanization in China,more and more buildings,bridges,roads and other infrastructure are built,and the number of engineering is growing.It will seriously affect the efficiency of the demolition work,and even affect the whole process of urbanization if we simply rely on manual removal operations.In addition,although the traditional blasting demolition method can quickly and widely complete the demolition work,there is always a security problem that traditional blasting demolition method can not be used in those places especially such as schools,residential areas and commercial center and other crowded areas.With the acceleration of our social development process,the cycle of cement pavement and renovation is becoming shorter and shorter,and the quality of road surface is getting higher and higher.As a result,the road surface hardening and maintenance work are becoming more and more frequent.Due to artificial destructive power and the human body can withstand the continuous demolition of the duration of the operation is limited,relying on manual demolition simply will not only seriously affect the progress of the work,but also will cause some damage to the body of the demolition workers.However the emergence of demolition machinery not only greatly improve the ability to finish the demolition operations,but also makes the demolition work more safe and efficient,and keeps the workers' safety from the body harm.Compared to large and medium-sized demolition machinery,the tire-type cement road demolition vehicle which has been studied in this paper has more smaller volume and lighter weight,and it is able to move flexibly and can finish demolition operations on the narrow road.In addition,a lightweight hydraulic hammer is installed at the end of the mechanical arm,which can completely meet the demolition work of the ordinary cement road surface.According to the measurement of the tire-type cement road demolition vehicle size,the vehicle model has been created by the three-dimensional modeling software,and then,based on the equivalent stiffness theory,the simplified model has been established which is used in the following analysis.In this paper,the static theory calculation of the tire-type cement pavement demolition vehicle has been done to solve the situation of forced vehicle body in work and the limiting angle of road surface tilt on which demolition vehicle does demolition work,which provide a certain reference for the demolition work.And then the finite element analysis of the stress and deformation of the vehicle body has been done which has found out some potential problems and provide directions for later optimization.In this paper,the dynamic characteristics of the vehicle body are studied from the model analysis of the vehicle body and the analysis of the vibration characteristics of the vehicle body under the excitation of the engine and the hydrolic hammer.In the research,the modal analysis has been done to get advance understanding of the natural frequency and vibration mode of the vehicle body,and then set the excitation frequency range of harmonic analysis and measurement points refer to the results of modal analysis,and the harmonic response analysis was carried out under the excitation of the engine and the hydrolic hammer,according to the results of the analysis check whether the vehicle body will resonate,and point the direction for the late optimization.Establish the motion analysis model of mechanical arm,matrix method and Adams motion simulation software are used to calculate and simulate the trajectory of the working device to gets the limit working position of the end of the working device.And the length of the boom cylinder and the swing cylinder is obtained by calculating the limit state,thus,the two methods are verified by each other to ensure the accuracy of the trajectory which provides the basis for the better control of the mechanical arm in practical work.In the end,the effect of three kinds of weld on the stress change and vibration characteristics of the connecting parts of electromagnetic valve body and main column has been studied,and select the appropriate welding scheme to eliminate the stress concentration and has better vibration characteristics in which will keep the connecting parts of electromagnetic valve body and main column from failure because vibration.Finally,the four order natural frequency of the vehicle body is optimized by using multi-objective optimization analysis which will choose reasonable square pipe size to increase the natural frequency of the four order mode under the premise of keeping the minimum material quality,and then to avoid the vehicle body under the engine idling excitation resonance and to ensure the stability of the vehicle body.