| The Finite Element method is a popular numerical analysis method, which is widely applied in the field of engineering. But actually to get satisfied calculation result designers have to adjust the initial model of the finite element model for several times. Thus how to modify the finite element model without changing the topology structure of the model conveniently and frequently will be paid more and more attention. Such as, during the iteration of execution the shape optimization problem, how to re-new the finite element model with the current design variable without changing the topology structure of finite element model.In order to solve the existing problem of the software to the finite element at present, parameterized the data of the finite element, can convenient to get the same structure, different size finite element model and analysis results of component, and then optimize analyzing and design.The lift arm design of the all terrain crane is one of the most important aspect for the all terrain crane designer. With the expands of market, user's requirement became higher than before for capability of crane .great lengths of crane has a good perspective ,but traditional jib calculation methods can't satisfied the people's requirements. This paper provided much theoretical direction for this problem. The most frequent malfunction that happen to crane are overturn and breaking ,breaking of arm was caused by overweight and not enough intensity ,many people would died when accidents happen ,at the same time, economical lost are following, so it is important to study the arm of crane. Also the lift arm is one of the most import part of the all terrain crane. It is composed of telescopic boom and jib. In the process of the testing at the experiment field, we find the boom seldom appears a problem, but the jib again and again appears a problem, for example strength breakage and stability breakage. The main problem lies in the fact that at the initial stage to settle parameter, the calculation has great capacity and hand- checking computations have bad accuracy, usually different designer having different checking results. Worst, hand-checking computations are excessive to simplification and assumption of computation formula ,for example supposing the main boom up end turning angle to be 3～5°. Solving the problems above, we can consider the parameterized finite element analysis, but at the initial stage it is difficult to offer the practicality structure parameter and it takes a great more time to analysis and also it can not realize the calculation of the lift capability table. Therefore, parameterized finite element analysis is not suitable for the initial stage design. The program of PMS is a special modeling program developed for the crane jib of the truck crane industry. The implement of this program makes the crane jib designers disentangled from the boring and mixed modeling work, and makes the designers concentrate on the design and improvement of the crane jib structure, but not the mechanics analysis. By running the PMS program, designers will soon achieve the results of the designs or improvements, which will provide trustful data foundations of the new designs and improvements.It will be nothing for this special program development, if without the manual fining work as a premise. So we prepared a lot before programming. We fist analyzed the crane jib structure of the QAY100H and QAY350H truck crane, communicated sufficiently with the designers, and composed, with the designers, the structural analysis report, which is named"Finite Element Analyzing Report of Crane jib Structure Components of the QAY100H Truck Crane of Changsha ZhongLian PuanYuan Heavy Machinery Corporation Ltd."and"Finite Element Analyzing Report of Crane jib Structure Components of the QAY350H Truck Crane of Changsha ZhongLian PuanYuan Heavy Machinery Corporation Ltd.".We took a stress testing of the structure to validate the correctness of the computing model and the designers also participated in the collection of data to guarantee the objectiveness of the test. During the course of data processing, we communicated with the designers of the involved formulae and arithmetic. The designers and us together managed to establish and analyze the model, collect and deal with the testing data. The implement of the"Testing and Computing Data Analysis Report of Crane jib Structure Components of the QAY100H Truck Crane"Shows that we know and understand the crane structure correctly.Distilling the parameters was also accomplished with the designers and the amount of its workload was also very big. The designers and I used two weeks time to accomplish the elementary report"Explaining Text of Crane jib Structure Components Parameters of the Truck Crane", in which the designers considered the structural aspect and I considered the programming aspect.The programming of the PMS program was divided into two parts: one was the inner core, and the other was the interface. C language and the script language of the preceding disposal of the finite element analysis software ALGOR were used to program the inner core; This phase ended with the accomplishment of the"Explaining Text of Using the Parametric Modeling Program of QAY".The PMS program has a straight looking interface and simple operation, and provides an interface for the designer to design the crane jib structure in an efficient way. The PMS program reduces the difficulty for the common designers to apply the existence finite element analyzing software and ensures that the designers can establish the finite element analyzing model of the product structure quickly and correctly, so as to get the data which can be referenced.The parametric modeling program of the parts and components has already been used in many CAD 3-D modeling circumstances, however, because of the big frameworks'geometric and connecting complexity, it is significant to develop series tools to assist the designers to build the finite element analysis model and achieve the self-dependence development of the enterprise products. Programming this kind of parametric finite element modeling program for the concrete structure, which provides the interface of applying the existence general finite element analysis software for the designers, becomes a really practical work. This essay just implements the parametric modeling program of crane jib structure components of the truck crane, while other great structures'modeling program developments need more communications and cooperation from the enterprise. |
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