As a typical heavy apron feeder for sale, it is applied to the mining industry and mainly undertakes transportation operations. The main steel structure is the bearing and supporting part of heavy apron feeder for sale, whose strength, elastic deformation and dynamic characteristics directly affect the reliability of equipment. The study of steel structure performance is a very tedious process, its structure is complex, the size of the collection of elements is different, simple experience design is difficult to ensure the reliability of the structure, latent problems are difficult to find, so the traditional design can not fully meet the needs of the design. With the continuous development of computer software, the finite element method of elastic mechanics is used in most of modern important structural designs, which makes the design level significantly improved. In this paper, the steel structure of the heavy apron feeder for sale in the self-moving crushing station of an enterprise is taken as the research object, and the static and modal analysis is carried out to verify the strength and stiffness requirements of the steel structure of the feeder. To infer the stress and deformation state of unmeasured or unmeasured parts: to find out the weak link of structure and improve it has important theoretical reference and practical significance.
The heavy-duty apron feeder for sale in this paper can mainly bear two working conditions: one condition is that the feeder can transport materials smoothly with the load and there is no blanking impact chain plate; the other condition is that the feeder can blanking impact chain plate in the process of material transportation. In this paper, the static analysis and modal analysis of the main steel structure of the heavy apron feeder for sale under the first working condition are carried out
1.1 Construction of 3D Model The construction of 3D model is an important and critical step in the numerical simulation analysis. The main steel structure of the 3D model is welded by steel plates of different thicknesses. There are many welds between the model steel plates, resulting in different size gaps in the model, which brings difficulties to the subsequent finite element analysis. Moreover, the structure of the apron feeder for sale is complex and three-dimensional entity. In the process of establishing the finite element model, it is necessary to reasonably simplify the structure in order to establish the model under the premise of conforming to the mechanical characteristics of the structure:
Its main simplified description is as follows:
(1). Ignore some tiny features in the parts. Some tiny structures, such as bolt holes and fillet corners, have little influence on the accuracy of the results, so these tiny geometric elements are not considered in modeling:
(2) Process defects such as cracks and virtual welding are not allowed in all welding positions. It is considered that the material at the welding position is continuous and directly fills the gap;
There are many kinds of model accessories with complex shape, and they have little influence on the ground stiffness and strength of the frame. Only its self-weight can be considered in the calculation model, such as hopper, roller, apron, chain plate and other auxiliary equipment.
1.2 Material Properties
All the structural steels are made of Q235 carbon structural steels, whose geoelastic modulus E=2.1e11N/m2, density 7830kg/m3, shear modulus of Q235 are 81000Pa, Poisson ratio is 0.3, and the model material is isotropic. Table 1 Allowable stress list of material Q235: Pa(N/mm)
The number of finite element meshes is too small, which is easy to produce distortion and affect the calculation accuracy. However, if the number is too large, it not only has little effect on improving the accuracy, but also greatly increases the calculation workload. Therefore, before grid partitioning, the model is cut and bonded by Boolean calculation, and then the free partitioning method is adopted to meet the requirements of computational accuracy and computational quantity control. The unit type is three-dimensional solid unit So1id164. The size of the model ground unit is set to 100mm, and the finite element model after grid division is shown in Figure 1: generated after grid division: number of nodes: 391020 number of units: 56,282.
According to the finite element statics calculation results of steel structures on the apron feeder for sale, the ground stress of most structures is less than 150M P, which can meet the requirements of steel ground strength. The ground stress concentration at the constraint area is ignored, and the sudden position of the model can be processed with rounded corners to reduce the stress concentration. The maximum deflection of the main steel structure is also within the allowable range, which also meets the stiffness requirements.
(2) The natural frequency and vibration mode of the first 6 terraces of the steel structure are obtained through modal analysis, which provides important dynamic parameters for further response analysis of the main steel structure, and also provides theoretical reference for improving and optimizing the structural design.
