Mechanical Characteristics Analysis of Grinding Plate of Food Waste Grinding Mill Based on ANSYS Workbench

Food waste accounts for 30% - 50% of domestic waste, and its centralized treatment is difficult. For commercial places with large production of food waste, it is a better way to use grinding mill to crush food waste and then discharge it into sewer. The mechanical properties of grinding plate are the decisive factors affecting the performance of grinding mill. In this paper, the static analysis and modal analysis of the grinding plate of commercial grinding mill are carried out. The results show that: under the rated load, the maximum equivalent stress of grinding hammer is 83.4mpa, the maximum equivalent stress of cutter head is 77.6mpa, which meets the design requirements, but the stress is relatively concentrated. The lowest modal vibration frequency of the lapping plate is 456.2hz, and the lapping plate will not have resonance damage under normal conditions.

Experimental analysis on mechanical properties of BF/PLA composites and its lightweight design on power battery box

In response to the concept of energy conservation and environmental protection, a novel composite battery box with BF/PLA composite is proposed. Firstly, the mechanical properties of BF/PLA composite are tested, and it is concluded that the property parameters of BF/PLA composite with 50% BF mass fraction is selected as the material property parameter of subsequent finite element simulation. Subsequently, the statics analysis and constraint modal analysis of the traditional metal battery box are carried out under the typical working conditions of rapid turning and braking under vertical bumping. Based on this, the upper and lower box materials of the battery box except the bracket are replaced by BF/PLA composite. The morphology optimization, topology optimization and free size optimization are carried out with the constraint that the first-order modal vibration frequency is no less than 30 Hz. Compared with the traditional metal battery box, the stiffness and strength of the optimized BF/PLA composite battery box are significantly enhanced. Moreover, the first-order constraint modal frequency increases by 15.5%, and the comprehensive weight reduction ratio reaches 40.88%. Finally, the optimized BF/PLA composite battery box is verified under random vibration, mechanical shock analysis, collision analysis, extrusion and falling ball analysis and drop analysis conditions. Meanwhile, compared with the traditional metal battery box under the same working conditions, the excellent reliability of the composite battery box is highlighted. The proposed BF/PLA composite battery box satisfies the requirements of stiffness and strength performances under various working conditions, which provides theoretical and data support for the application of composite materials in battery box and other automotive components.

Modal analysis of a membrane structure with actuators

The aim of this paper is the analysis of the modal vibration of the membrane structure. Membranes are defined as structures of the lightweight architecture and they are currently very popular. They have a long history and development, in which they have reached a stage where we can complement them with action elements, also called actuators. These elements can change their length and thus affect a stress state of a membrane, which allows more efficient use. In addition to a static analysis, it is necessary to subject structures to a dynamic analysis, in this case we deal with the natural vibration. This modal analysis deals with the first 5 mode shapes and their dependence on the change in the length of the actuators. This initial calculation will be followed by a forced vibration analysis in the future.

Performance of Five-Axis Machine Tool and Intelligent Machining Process

In this study, the processing performance of a five-axis machine tool was analyzed to identify processing weaknesses as the basis for subsequent structural improvements. Data were then integrated through the Abductory Induction Mechanism (AIM) polynomial neural network to predict intelligent processing quality, and an in-depth investigation was conducted by importing processing parameters to predict the surface quality of the finished product.The finite element analysis method was used to analyze the static and dynamic characteristics of the whole machine and to test the structural modal frequency and vibration shape. For modal testing, the experiment used various equipment, including impact hammers, accelerometers, and signal extractors. Subsequent planning of modal frequency band processing experiments was conducted to verify the influence of natural frequencies on the processing level. Finally, according to the machine processing characteristics, a processing experiment was planned. The measurement record was used as the training data of the AIM polynomial neural network to establish the processing quality prediction model.After analysis and an actual machine test comparison, the three-axis static rigidity values of the machine were X: 1.63 Kg/µm, Y: 1.93 Kg/µm, and Z: 3.95 Kg/µm. The modal vibration shape maximum error of the machine was within 6.2%. The processing quality prediction model established by the AIM polynomial neural network could input processing parameters to achieve the surface roughness prediction value, and the actual relative error of the Ra value was within 0.1 µm.Based on the results of cutting experiments, the influence of the dynamic characteristics of the machine on the processing quality was obtained, especially in the modal vibration environment, which had an adverse effect on the surface roughness. Hence, the surface roughness of the workpiece processed by the machine could be predicted.

A semi-active shunted piezoelectric tuned mass damper for robust vibration control

Tuned mass dampers are well-known devices for efficient reduction of structural vibrations; however, they can only control the vibration of a single mode in a narrow frequency range and are not easily retunable. This article presents a semi-active tuned mass damper, consisting of a piezoelectric device connected to an external resistive–inductive electric circuit, which enables multi-modal vibration control, is highly tunable, and introduces high damping. The dynamics of the coupled electromechanical system, which includes the primary and auxiliary masses, the piezoelectric device, and the shunt circuit, are analyzed and the effect of the resistance and inductance is investigated. An experimental prototype using a specialty piezoelectric device is fabricated and tested. The experimental measurements greatly agree with the analytical results, validating the strong electromechanical coupling and the enhanced vibration suppression capabilities of the proposed damper. Moreover, the variation of inductive impedance demonstrates substantial semi-active broadband multi-modal vibration control potential, by introducing an additional highly tunable electromechanical resonant oscillator in the system dynamics, and also by enabling the enhancement of coupling and energy dissipation on targeted modal frequencies.

Mode Shape Description and Model Updating of Axisymmetric Structures Using Radial Tchebichef Moment Descriptors

A novel approach for mode shape feature extraction and model updating of axisymmetric structures based on radial Tchebichef moment (RTM) descriptors is proposed in this study. The mode shape features extracted by RTM descriptors can effectively compress the full-field modal vibration data and retain the most important information. The reconstruction of mode shapes using RTM descriptors can accurately describe the mode shapes, and the simulation shows that the RTM function is superior to Zernike moment function in terms of its mathematical properties and its shape reconstruction ability. In addition, the proposed modal correlation coefficient of the RTM amplitude can overcome the main disadvantage of using the modal assurance criterion (MAC), which has difficulty in identifying double or close modes of symmetric structures. Furthermore, the model updating of axisymmetric structures based on RTM descriptors appears to be more efficient and effective than the normal model updating method directly using modal vibration data, avoids manipulating large amounts of mode shape data, and speeds up the convergence of updating parameters. The RTM descriptors used in correlation analysis and model updating are demonstrated with a cover of an aeroengine rig. The frequency deviation between the test and the FE model was reduced from 17.13% to 1.23% for the first 13 modes via the model updating process. It verified the potential to industrial application with the proposed method.