Structural Performance Optimization Research Articles

Structural Performance Optimization Design of Continuously Accelerating Electromagnetic Weft Insertion System

This paper addresses the problem of low electromagnetic weft insertion acceleration performance of extra-large width automatic looms. Based on single-stage electromagnetic weft insertion and multi-stage intermittent electromagnetic weft insertion, a sectional combined continuous acceleration electromagnetic weft insertion design plan is proposed. First, a new type of weft gripper for electromagnetic weft insertion is designed on the basis of the traditional projectile, and a segmented combined structure optimization design is carried out on the 90 mm single-stage coil. Next, the electromagnetic weft insertion movement model is established to analyze the force and movement speed of the gripper during the movement. The amount of work done by the electromagnetic force of the combined coil determines the exit speed of the weft gripper. Finally, in order to find the best parameters of the combined coil structure to meet the requirements of the launch speed, the steady state and transient performance of the segmented combined continuous acceleration coil are analyzed using Maxwell simulation software. The launch performance of the combined coil with different axial lengths of 45 mm, 30 mm, and 15 mm is compared. The results show that the entire acceleration process is more stable and efficient when the combined coil length is 30 mm, the inner diameter is 18 mm, and the number of turns is 600.

Structural Performance Optimization and Verification of an Improved Thin-Walled Storage Tank for a Pico-Satellite

This paper presents an improved mesh storage tank structure obtained using 3D metal printing. The storage tank structure is optimized using a multi-objective uniform design method. Each parameter influencing the storage tank is considered as the optimization factor, and the compression stress (
 
 
 σ
 
 
 ), volume utilization ratio (
 
 
 v
 
 
 ), and weight (
 
 
 m
 
 
 , are considered as the optimization objectives. Regression equations were established between the optimization factors and targets, the orders of the six factors affecting three target values are analyzed, and the relative deviations between the regression equation and calculation results for 
 
 
 σ
 
 
 , 
 
 
 v
 
 
 , and 
 
 
 m
 
 
 were 9.72%, 4.15%, and 2.94%, respectively. The optimization results showed that the regression equations can predict the structure performance of the improved storage tank, and the values of the influence factors obtained through the optimization are effective. In addition, the compression stress was improved by 24.98%, the volume utilization ratio was increased by 26.86%, and the weight was reduced by 26.83%. The optimized storage tank was developed through 3D metal printing, and the compressive stress was improved by 58.71%, the volume utilization ratio was increased by 24.52%, and the weight was reduced by 11.67%.

Visualized Analysis and Simulation Research on Dynamic Performance of the Whole NC Machine Tool

The dynamic performance of numerical control (NC) machine is not only basis of evaluation for the vibration resistance and stability, but also theory basis of optimizing dynamic performance, and improving processed quality. As digital design method, visual design realizes "visibility" during the whole design process, increases design efficiency and guarantees the quality, which make visual design preferred design method in large mechanical engineering. In this paper, the analysis of dynamic performance on NC machine and visual design method will be integrated, taking a NC machining center built by Shenyang machine tool group as a study case, the dynamic visual design flow to be proposed, including the design purpose, content and design methods, finally, the dynamic performance of visual simulation we have done, taking the strength, inherent characteristics and harmonic response into account, offers the foundation about structural performance optimization on the machine.

Reliability analysis of laminated composite structures using finite elements and neural networks

Saving of computer processing time on the reliability analysis of laminated composite structures using artificial neural networks is the main objective of this work. This subject is particularly important when the reliability index is a constraint in the optimization of structural performance, because the task of looking for an optimum structural design demands also a very high processing time. Reliability methods, such as Standard Monte Carlo (SMC), Monte Carlo with Importance Sampling (MC–IS), First Order Reliability Method (FORM) and FORM with Multiple Check Points (FORM–MCPs) are used to compare the solution and the processing time when the Finite Element Method (FEM) is employed and when the finite element analysis (FEA) is substituted by trained artificial neural networks (ANNs). Two ANN are used here: the Multilayer Perceptron Network (MPN) and the Radial Basis Network (RBN). Several examples are presented, including a shell with geometrically non-linear behavior, which shows the advantages using this methodology.

Analysis and optimization of energy flows in structures composed of beam elements – Part I: problem formulation and solution technique

The paper addresses the analysis of in-plane coupled flexural and longitudinal vibrations of a structure composed of elastic tubular beams. Emphasis is put on optimization of structural performance in terms of minimization of total power flow over a broad-banded frequency range, i.e. minimization of the emitted/trans- mitted energy of vibrations. The objective function is chosen as an energy outflow (a structural intensity) integrated within the given frequency range at a given remote point (cross-section) of the tubular structure. To gain insight into the physical mechanisms of energy transportation, the structure is decomposed into a set of elementary dynamical systems. These elementary dynamical systems (subsystems) are chosen as one-dimensional wave-guides carrying either longitudinal or flexural waves. Vibrations of each dynamical subsystem are described by a boundary equation method, a novel method in structural dynamics which ideally fits the substructuring concept since it deals with physical variables at boundaries between substructures, no matter what type of excitation is applied at individual substructures. A system of boundary integral equations is accomplished by continuity conditions at interfaces between subsystems and by boundary conditions. Since Green's functions used in the boundary integral formulation satisfy the radiation principle, the governing system of equations is equally applicable for analysis of vibrations of both finite-length structures and the structures having infinitely long elements jointed with elements of finite length.