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Excessive tire wear can affect vehicle driving safety. While there are various methods for predicting the tire wear amount in real-time, it is unclear which method is the most effective in terms of the difficulty of sensing and prediction accuracy. The current study aims to develop prediction algorithms of tire wear and compare their performances. A finite element tire model was developed and validated against experimental data. Parametric tire rolling simulations were conducted using various driving and tire wear conditions to obtain tire internal accelerations. Machine-learning-based algorithms for tire wear prediction utilizing various sensing options were developed, and their performances were compared. A wheel translational and rotational speed-based (V and ω) method resulted in an average prediction error of 1.2 mm. Utilizing the internal pressure and vertical load of the tire with the V and ω improved the prediction accuracy to 0.34 mm. Acceleration-based methods resulted in an average prediction error of 0.6 mm. An algorithm using both the vehicle and tire information showed the best performance with a prediction error of 0.21 mm. When accounting for sensing cost, the V and ω-based method seems to be promising option. This finding needs to be experimentally verified.

High-pressure air storage is an important part of a gas storage system. Abandoned coal mine roadways can provide a large number of air storage spaces. The geological conditions of coal mines in different areas vary, such as depth, surrounding rock grade, in situ stress state, and surrounding rock permeability, which directly affect the mechanical behavior and air tightness of roadway surrounding rock under high internal pressure. Therefore, the suitable internal pressure must be selected for abandoned roadways with different geological conditions. In this study, the numerical simulation software FLAC3D was used to calculate the stress, deformation, plastic zone volume, and pore pressure of surrounding rock of an abandoned roadway under 5–10 MPa internal pressure. Results show that some differences exist in the suitable internal pressure of the abandoned roadway under different geological conditions. When the in situ stress state was σH > σh > σv or σH > σv > σh, the suitable internal pressure of grade I, II, and III surrounding rocks was 5–7 and 8–10 MPa at the depth greater than 200 and 300 m, respectively; the suitable internal pressure of grade IV and V surrounding rocks was 5–6, 7–9, and 10 MPa at the depth greater than 200, 300, and 400 m, respectively. When the in situ stress state was σv > σH > σh, the suitable internal pressure of grade I, II, III, IV, and V surrounding rocks was 5–7 and 8–10 MPa at the depth greater than 300 and 400 m, respectively. Surrounding rock permeability can be used to evaluate the air tightness of roadway surrounding rock under high-pressure air. The surrounding rock permeability that can meet the sealing requirements of compressed air energy storage (CAES) caverns is less than 1 × 10−14 m2, which are low-permeability strata. Low-permeability hard rock should be selected as much as possible. The research results provide a theoretical basis for the determination of internal pressure and the sealing evaluation of an abandoned coal mine roadway used for gas storage cavern.

Glass-fiber-reinforced plastic (GFRP) composite pipes are used extensively in high-performance applications, due to their high stiffness and strength, corrosion resistance, and thermal and chemical stability. In piping, composites showed high performance due to their long service life. In this study, glass-fiber-reinforced plastic composite pipes with [±40]3, [±45]3, [±50]3, [±55]3, [±60]3, [±65]3, and [±70]3 fiber angles and varied pipe wall thicknesses (3.78–5.1 mm) and lengths (110–660 mm) were subjected to constant hydrostatic internal pressure to obtain the pressure resistance capacity of the glass-fiber-reinforced plastic composite pipe, hoop and axial stress, longitudinal and transverse stress, total deformation, and failure modes. For model validation, the simulation of internal pressure on a composite pipe installed on the seabed was investigated and compared with previously published data. Damage analysis based on progressive damage in the finite element model was built based on Hashin damage for the composite. Shell elements were used for internal hydrostatic pressure, due to their convenience for pressure type and property predictions. The finite element results observed that the winding angles from [±40]3 to [±55]3 and pipe thickness play a vital role in improving the pressure capacity of the composite pipe. The average total deformation of all designed composite pipes was 0.37 mm. The highest pressure capacity was observed at [±55°]3 due to the diameter-to-thickness ratio effect.

In previous studies, the numerical simulation models of industrial airbags were verified to have high accuracy regarding their actual dynamics. However, numerical methods were scarcely utilized to simulate and investigate the inflation height behaviors of nursing bed airbag. For this problem, this study constructs a numerical simulation model illustrating the association between the internal pressure and inflating height of nursing bed airbag, under various external loads. Firstly, based on an averaged pressure prerequisite, an airbag dynamic model is established by the control volume approach (the air inside the airbag follows the gas state equation of Poisson’s law). Besides, the elastic mechanical behaviors of airbag film material are determined according to a material constitutive model built by the quasi-static uniaxial tensile test. The obtained data are used as the boundary conditions, for the numerical dynamics modeling of the nursing bed airbag. Verification experiments clarify that this numerical modeling is accurate for describing airbag inflation behaviors, and then can be effectively applied to the design and optimization phases of nursing bed airbags. Based on the simulation modeling above, the mathematical equation of controlling airbag inflating height by its internal pressure is obtained. It provides a vital basis for the differentiated and intelligent control of the airbag nursing bed. Graphical abstract

THFG is an advanced technology to manufacture tubular components with complex cross-sections. Meanwhile, curved axis often exists in such components, which is formed by pre-bending steps before THFG. However, the effect of pre-bending on the subsequent THFG, especially on the critical internal pressure required to inhibit wrinkling, has not been clarified yet. Considering the difference in the cold work-hardening and the thickness distribution caused by pre-bending, the change rule between the critical internal pressure and the hoop strain was re-established based on the energy method. It is found that the cold work-hardening has a great influence on the change rule. Subsequently, by solving the three-dimensional mechanics condition of single and double curvature differential segments respectively, the distribution of hoop strain after THFG was obtained by combining pre-bending. Pointing out that the initial thickness has an obvious effect on the hoop strain distribution, while the cold work-hardening is almost negligible. The maximum hoop strain was brought into the change rule between critical internal pressure and hoop strain, then, a new analytical model between the critical internal pressure and the punch stroke considering pre-bending was built. The critical internal pressure considering pre-bending is determined by that of outer straight wall, and its value is always greater than the critical internal pressure without considering pre-bending under the same punch stroke. With the reduction of bending radius, the critical internal pressure distinction between considering and not considering pre-bending will be greater. Moreover, the smaller the friction coefficient also will lead the distinction to be more prominent. In this work, our proposed new prediction model of critical internal pressure is meticulously demonstrated, which can improve the accuracy by 74% at least when existing the pre-bending.

A modified numerical procedure for the shakedown analysis of structures under dual cyclic loadings, based on the Abdalla method, is proposed in this paper. Based on the proposed numerical procedure, the shakedown analysis of the thick cylindrical vessels with crossholes (TCVCs) under cyclic internal pressure and cyclic thermal loading was carried out. The effects of material parameters (elastic modulus and thermal expansion coefficient) and crosshole radius on the elastic shakedown limit of TCVCs are discussed and, finally, normalized and formularized. Furthermore, the obtained shakedown limit boundary formulation is compared with FEA results and is verified to evaluate the shakedown behavior of TCVCs under cyclic internal pressure and cyclic thermal loading.

Due to the growth of the population in urban areas, metro tunnels are the most important means of transportation. Hence, it is necessary to study the tunneling conditions and their effects on the nearby structures. In addition, internal tunneling pressure and groundwater level changes affect the ground surface displacements, significantly. This research considered the changes of the groundwater level and the uniform internal pressures simultaneously in simulating the earth pressure balance (EPB) shield tunneling method before the tunnel lining installation. The study applied a series of 2D finite element models of the tunnel longitudinal and transverse sections to evaluate the Isfahan metro's surface displacements and the optimum internal pressure. Mohr–Columb constitutive model and the plane strain assumption were adopted in numerical simulations. Different types of failure mechanisms of the ground surface in the longitudinal section were proposed by concentrating in vertical and horizontal displacements. The results showed that uniform internal pressure equal to 300 kPa caused the minimum ground surface displacements in the Isfahan metro project.

Purpose This study aims to provide a theoretical basis to evaluate the suitability and integrity of corrosion pipes. Design/methodology/approach The three-dimensional models of the P110S oil pipe with local corrosion damage, general corrosion damage, pitting corrosion damage are established based on the API 579 standard using the nonlinear finite element analysis method for parametric research. Findings The reliability of the model is verified based on the experimental data from the existing literature. The effects of the oil pipe’s size and the corrosion damage’s type on the residual internal pressure strength are simulated and obtained. What’s more, a basic method for predicting the remaining life of corrosion damaged pipes is proposed. Originality/value The authors evaluated the residual strength of various corroded tubing, compared the tubing with different corrosion types and proposed a basic method for predicting the remaining life of the corroded tubing from the corrosion depth.

Dome curvatures of pressure vessels often sustain highest level of stresses when subjected to various loading conditions. This research is aimed at investigating the effect of dome geometrical shape (hemispherical, torispherical, and ellipsoidal domes) on mechanical deformation and crack length of laminated woven reinforced polymer (GRP) composite pressure vessels under low-velocity impact (LVI) (case one) or combination of LVI and internal pressure (case two). The study is based on finite element (FE) simulations with laboratory-based experimental validation studies. It was observed that the maximum vertical displacements (U1*) and crack length along the diameter of deformation (a) are both of lower magnitude in case one. Damage intensity and fracture differ for different combinations of loading. Only matrix breakage and debonding occurs in case one and fiber breakage occurs in case two. The dome geometric shapes used in this study were found to be invariant to both damage intensity and failure modes. Irrespective of the type of load applied, the magnitude of U1* and crack length correlate with dome geometric shape as the maximum and the minimum U1* occur in torispherical and hemispherical domes, respectively. The maximum and the minimum crack lengths also take place in torispherical and hemispherical domes, respectively.

The vortex in a pump sump is a negative problem for the pump unit, which can lead to the decline of pump performance. Focusing on the internal pressure characteristics of the floor-attached vortex (FAV) and its influence on the pump unit, the FAV was analyzed adopting the previously verified numerical simulation method and experiment. The results show that the pressure in the vortex core gradually decreases with time, drops to a negative pressure at the development stage, and then reaches the lowest pressure during the continuance stage. When the negative pressure of the vortex tube is around the vaporization pressure of the continuance stage, it can cause a local cavitation at the impeller inlet. The evolution of the FAV is accompanied by a change of pressure gradient in the vortex core which is discussed in detail. This research provides theoretical guidance for a better understanding of the vortex characteristics and the optimal design for the pump.