Numerical Application of Effective Thickness Approach to Box Aluminium Sections

The ultimate behaviour of aluminium members subjected to uniform compression or bending is strongly influenced by local buckling effects which occur in the portions of the section during compression. In the current codes, the effective thickness method (ETM) is applied to evaluate the ultimate resistance of slender cross-sections affected by elastic local buckling. In this paper, a recent extension of ETM is presented to consider the local buckling effects in the elastic-plastic range and the interaction between the plate elements constituting the cross-section. The theoretical results obtained with this approach, applied to box-shaped aluminium members during compression or in bending, are compared with the experimental tests provided in the scientific literature. It is observed that the ETM is a valid and accurate tool for predicting the maximum resistance of box-shaped aluminium members during compression or in bending.

Evaluation Method of the Gas Hydrate and Free Gas System and Its Application in the Shenhu Area, South China Sea

As a new alternative energy source, gas hydrate has attracted wide attention all over the world. Since gas hydrate is always associated with free gas, the evaluation of the gas hydrate and free gas system is an important aspect of hydrate reservoir exploration and development. In this study, based on identifying gas hydrate and free gas by well logging, the seismic reflection characteristics of gas hydrate and free gas are determined by an accurate well-to-seismic calibration method. On account of seismic reflection characteristics, AVO attributes are used to identify gas hydrate and free gas qualitatively. Using prestack and poststack inversion to get the ratio of P -wave impedance and P -wave-to- S -wave velocities, we determine the three-dimensional space distribution of gas hydrate and free gas, predict their effective porosity and saturation, and eventually achieve the meticulous depiction of gas hydrate and free gas in the body, which is necessary in subsequent estimation of gas hydrate and free gas resources. Results show that according to logging interpretation, gas hydrate of the B-well is located in the depth range of 1460–1510 mbsl and free gas is in 1510–1542 mbsl. Moreover, gas hydrate of the A-well is located in the depth range of 1425–1512 mbsl, and no obvious free gas is identified. Gas hydrate is located above free gas and distributed continuously. In plane form, gas hydrate and free gas both present subelliptical distribution in the NW-SE direction. Gas hydrate has an effective porosity of 0.30–0.40, an average saturation of 0.33–0.40, and an effective thickness of 3.0–10.5 m, whereas free gas possesses an effective porosity of 0.35–0.40, a saturation of 0.24–0.32, and an effective thickness of 2.0–5.0 m.

Calculating the effective thickness of the thermal barrier coating

The paper presents the results of numerical simulation of heat transfer at the interaction of a hot impact nitrogen jet with a ceramic thermal barrier coating 7YSZ based on ZrO2 with the addition of 7% Y2O3. The radiant component of heat transfer is shown to make a significant contribution to the final temperature distribution on the surface of the protected product.

OPTIMIZATION OF POWDER COATING PROCESS PARAMETERS IN MILD STEEL (SPCC-SD) TO IMPROVE DRY FILM THICKNESS

This study presents a comprehensive review of the improved optimization for powder coating process variables in mild steel (SPCC-SD). The effective thickness of the dry film thickness (DFT) keeps a significant influence on the critical protection of mild steel against rust. In the powder coating process, the variable thickness is one of the primary and difficult objectives to accurately control the desired consistency. This empirical study properly uses RAL 7040 epoxy-polyester with the required thickness between 70-100 microns. This empirical study aims to reasonably achieve the optimal value of the effective thickness of the powder layer from specific combinations of specified process criteria. Practical experiments were properly conducted out manipulating an orthogonal Taguchi L16 array of independent variables; program, distance, application method, and the number of layers. This optimization method has been successfully upgraded. The average thickness of the powder coating layers reaches 84.85 microns. For a given limit, the application-method of typically preventing the determined cause correctly examined efficiently provides the most significant effect on effective thickness with an S/N ratio of 0.91. In the future, the relevant research may use our corresponding results to improve the powder coating procedure for other significant impacts.