Improving the robustness of DI and PVI further using fast guided filter on radiographic images

To further improve the robustness of the weld defect index (DI) and peak-valley index (PVI), which are key indices for detecting weld defects in radiographic testing (RT) images accurately and reliably, a robust improvement method is proposed, in which a fast guided filter (Fast-GF) is introduced and its effect on the DI and PVI is analysed. In this paper, the principle of the proposed robust improvement method, the related theory of Fast-GF, the definition and the calculational method of the DI and PVI are systematically analysed. Taking some practical RT images from industrial welding as an example, smoothing experiments with different filters and comparative computational experiments for the DI and PVI both with and without Fast-GF are carried out. The experimental results show that the robustness of the DI and PVI is further improved by the proposed robust improvement method, which is a desirable outcome. More specifically, the values of the DI and PVI are computed accurately and reliably regardless of some non-uniform distribution of grey levels, noise, irregular surfaces and artefacts in the RT images.

A Dual Frequency Ultrasonic Cleaning Tank Developed by Transient Dynamic Analysis

At present, development of manufacturer’s ultrasonic cleaning tank (UCT) to match the requirements from consumers usually relies on computer simulation based on harmonic response analysis (HRA). However, this technique can only be used with single-frequency UCT. For dual frequency, the manufacturer used information from empirical experiment alongside trial-and-error methods to develop prototypes, resulting in the UCT that may not be fully efficient. Thus, lack of such a proper calculational method to develop the dual frequency UCT was a problem that greatly impacted the manufacturers and consumers. To resolve this problem, we proposed a new model of simulation using transient dynamics analysis (TDA) which was successfully applied to develop the prototype of dual frequency UCT, 400 W, 18 L in capacity, eight horn transducers, 28 and 40 kHz frequencies for manufacturing. The TDA can indicate the acoustic pressure at all positions inside the UCT in transient states from the start to the states ready for proper cleaning. The calculation also reveals the correlation between the positions of acoustic pressure and the placement positions of transducers and frequencies. In comparison with the HRA at 28 kHz UCT, this TDA yielded the results more accurately than the HRA simulation, comparing to the experiments. Furthermore, the TDA can also be applied to the multifrequency UCTs as well. In this article, the step-by-step development of methodology was reported. Finally, this simulation can lead to the successful design of the high-performance dual frequencies UCT for the manufacturers.

The Influence of Raft Foundation Temperature Stress Calculation by Radiation Condition

Raft foundation was researched in this paper,basing on the traditional “Wang Tiemeng Method”,the influence of temperature stress calculation by radiation condition was put forward emphatically. According to analysis the two calculation results, obtains the more precise temperature stress calculational method. Consequently the of concrete crack calculation and analysis result can be more precise and reliable.

Calculation method for the continuum states of atomic systems

In the present work, we develop a calculational method of solving the scattering equations for spherically symmetric potentials by expanding the solutions on Coulomb functions. We utilize a multistep integration scheme together with the standard partial wave analysis in a region where the potential term dominates. The method applies to any physical problem expressed as [∇ 2 + V(r) + k 2]ψ(r) = 0, while the extension of the method to more general scattering problems is briefly discussed. At present, we demonstrate a two-step Coulomb-fitted integration scheme by calculating the short-range scattering phase shifts for various potentials V (r).

A study on the asynchronous brake lock-up of a statically indeterminate tractor with an air suspension

The paper aims to resolve the practical problems of asynchronous brake lock-up which acts on the wheels of statically indeterminate tractors with an air suspension. First, two kinds of deflection model are calculated, both of which are under the combined effect of the brake force and the vertical force. One model considers the leaf spring suspension that is mounted on the front axle, and the other considers the air suspensions that are mounted on both the midlift axle and the drive axle. Second, a 12-degree-of-freedom braking force distribution model of the statically indeterminate multi-axle tractor–semitrailer is constructed on the basis of the foregoing preparation. Third, the ideal braking forces of each axle in the model are simultaneously calculated and the actual braking forces of each axle are measured by road tests. The curves of the ideal and the actual braking force distribution ratios at different brake rates are described. The contradistinctive outcome indicates that the excessive braking force of the midlift axle results in a premature brake lock-up, which is the main reason why wheels lock asynchronously. Finally, because of the analysis of the distribution ratios of the ideal and the actual braking forces, the paper outlines how to redesign the braking force distribution of the tractor–semitrailer according to ECE R13, SAE J992b, and JASO C514. The paper also proposes a definition of and calculational method for the fitting degree (FD), and the FD of the midlift axle is improved from 61.2 per cent to 91.8 per cent. Compared with the original tractor–semitrailer, not only is the actual braking force distribution more reasonable but also the brake stability is improved.

Study on the Relations between the Structural Parameters and the Dynamics Properties

The general rule that the modal parameters of linear system change with the structural parameters was discussed. The calculational method of the change of modal parameters was given on the basis of the current modal parameters and the change pattern variation of structural parameters. An example indicated that this method can greatly save computational time than repeated modal analysis. Withal, the qualitative conclusions of the change of modal parameters can be expediently gained. These results are important to amelioration and optimization design of systems.

Foundation and Primary Exploration for the Woven Plaid System of Check Pattern Size and Parameter Changes

The paper gets the calculational method of check size in theory by discussing the effect factors of forming woven plaids. It realizes a calcuiation and design system of plaid by computer aided design. Meanwhile, by combining with the typical Tianzige and Jiugongge, the paper discusses the change regularity of check shaping parameters as a result of the change in check size and fabric density, and realizes a autogeneration system of the new check parameters.