| Wheel loader is a kind of Engineering Machinery widely used in many fields, which always be used to load and transport materials in the surface mine or engineering construction sites. Its working environment is always terrible and complex, so the structural element can be easily damaged in the work process. The front frame is a pivotal basic part of loader which supports the work equipment and connects the back frame. Whether its structure's layout is reasonable, will affect the capability of work equipment. The front frame will carry the loads which come from the work equipment and the drastic impact load when the loader running and working in the bumpy road. So it is especially important to carry on the kinematics and dynamics simulation of the work equipment and carry on the strength analysis of the front frame at the beginning of design.Papers, which based on the modern machine design methods: Virtual Prototyping Technology and Finite Element Analysis. The three-dimensional model of the loader's work device and the front frame are built by using Pro/E software.At first, loading condition of loader in the working process is analyzed, and then the Virtual Prototyping is established in the dynamics software ADAMS, the Kinematic/Dynamic simulation are achieved. The purpose of kinematic simulation is to analyze the interference between the structural element of the work device, the maximum dumping height and the motion trail of loader. The dynamic simulation of the loader which simulates the multiplexed work action under symmetrical load and bias load is achieved, the stress time curve of the hinge point on the front frame is gotten. The curve is the data base of the finite element analysis of the frame.Importing the geometric model of front frame into the FEA software ANSYS, building the FEA model, finding the corresponding load according to the several typical working condition and the curve, and then apply the load on the front frame, at last the stress and displacement contour figure of the front frame under each work condition is gotten by the static strength analysis. By analyzing the result of the static strength analysis, the weak point on the front frame is found; the local structure is optimized and improved which makes the distribution of the stress and displacement more reasonable. From the displacement contour figure and the contour figure ,we can find that the maximum stress and displacement of the front frame have obviously decreased. Under the work condition of symmetrical load and maximum breakout force, the value of the maximum stress have shrink from 420Mpa to 273Mpa, the value of the maximum displacement have shrink from 1.568 to 1.158mm.Under the work condition of bias load and Maximum drawbar pull, the value of the maximum stress have shrink from 430Mpa to 264Mpa, the value of the maximum displacement have shrink from 2.684mm to 1.979mm.Under the work condition of bias load and maximum breakout force, the value of the maximum stress have shrink from 503Mpa to 307Mpa, the value of the maximum displacement have shrink from 1.956mm to 1.452mm. The analysis result indicated that the stress and the strain distribution of the frame is more reasonable after the structure's optimization. The natural frequency and vibration mode of the front frame were gotten after a modal analysis, which will be combined with the exciting frequency of the engine to provide the basis to frame's further optimal design and design vibration isolation in the future. By using the Virtual Reality and FEA methods to research the work device and the front frame of the wheel loader, which can provide the theory support for the structural design of wheel loader's work device and the front frame. |
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