Research On The Stability Of Automobile Crane Working On The Deformed Ground

Automobile crane is one of engineering machines being widely used in engineering construction,and its stability directly affects the safety of automobile crane.The past studies on the stability of automobile cranes often took no account of ground deformation,but many safety accidents of automobile cranes are caused by the working ground deformation.Taking the automobile crane and the working ground as a unified system,the stability of automobile crane working on the deformed ground are studied in this thesis,which has certain engineering application value.According to the terramechanics theory,the relationship between ground pressure and subsidence under the action of crane landing legs are analyzed.the ground pressure under different soil parameters-subsidence relationship curve and the pressure of soil-body under different deformation index n and deformation modulus E-the influence law of subsidence curve are obtained based on MATLAB software for programming calculation.In order to compare with the stability of automobile cranes under rigid ground conditions,the working stability of automobile cranes on horizontal rigid ground are studied.The formula of dynamic stability coefficient and critical lifting quality of automobile cranes on horizontal ground are derived.The influence of slope angle,inertia force and wind load on working stability of automobile crane are studied to obtain their influence rules,and the influence degree of various factors on the automobile cranes are analyzed.According to the terramechanics theory,the formula of dynamic stability coefficient and critical lifting quality of automobile cranes on horizontal ground are deduced,and the influence of soil parameters on the stability of automobile cranes is analyzed.The stability of cranes is studied when considering the continuous deformation of the ground,and the formula for calculating the dynamic stability coefficient and critical lifting quality of the crane is deduced when considering the continuous deformation of the ground.In addition,the change law of stability coefficient and critical starting weight of the crane working on the deformation of the ground and the continuous deformation of the ground are obtained basedon MATLAB software programming.It is analyzed that the decreasing degree of dynamic stability coefficient under typical working conditions and considering the continuous deformation of the ground.The results of comparison and analysis of six typical working conditions show that inertia force and ground deformation have a great influence on the stability of automobile cranes.When working on deformed ground,we needs to pay attention to the change of soil characteristics,improve the evaluation standard of safety factor,and reduce the maximum lifting capacity.In this thesis,a three-dimensional model of an automobile crane is established in Solidworks,and a ground model is imported into ADAMS.The relationship between critical lifting mass and varying slope angle of the automobile crane under the deformed ground are analyzed.The simulation results and the theoretical calculation results are basically the same,which proves the feasibility of the simulation method.A method for studying the stability of automobile cranes on the deformed ground is provided.