Service Life Prediction of Type-IV Composite CNG Cylinder under the Influence of Drivers’ Refueling Habits—A Numerical Study

Abstract

The new generation presented for CNG fuel tanks of vehicles (type-IV) is made entirely of composites. The reason for that is to prevent the sudden explosion of metal tanks and to use the advantage of gas leakage in composite materials. Previous research has shown that type-IV CNG fuel tanks also have challenges such as variable wall thickness in outer shell parts, which are prone to failure under cyclic refueling loading. The optimization of this structure is on the agenda of many scholars and automakers, and in this regard, there are many standards for strength assessment. Despite reporting injury events, it seems that another parameter should be included in these calculations. In this article, the authors have attempted to numerically investigate the effect of drivers’ refueling habits on the service life of type-IV CNG fuel tanks. For this purpose, a 34-L CNG tank made of glass/epoxy composite, polyethylene, and Al-7075T6, respectively, for the outer shell parts, liner, and flanges was considered as a case study. Moreover, a real-size measurement-based finite element model validated in the corresponding author’s previous research was used. The loading history was applied as internal pressure according to the standard statement. Furthermore, considering different behavior of drivers for refueling, several loading histories with asymmetric details were applied. Eventually, the results obtained for different cases were compared to experimental data in symmetrical loading. The results showed that, based on the car’s mileage, the driver’s behavior in the refueling process can significantly reduce the service life of the tank (up to 78% of the predicted life based on the standard methodology).

The effect of the stress equilibrium factor on the composite case of the solid rocket motor

“…Chen [8] proposed that for the elliptical head with non-equal tension and the ellipsoidal ratio of 2, the stress equilibrium factor is generally taken as 0.7 empirically. Wang [9] proposed that the introduction of ks in calculating the thickness of the winding layer on the cylinder body of composite gas cylinders can ensure that the burst point occurs in the cylinder body, but did not specify the reason for this.In [10][11][12][13][14], researchers did not use the stress equilibrium factor in the calculation formula when designing the thickness of composite case winding layers. Zhang [15] considered the introduction of the stress equilibrium factor in the design of the thickness of the front and back head sections of the motor case, but the specific value of ks was not mentioned.…”

Quality Analysis of Natural Gas Using the Structural Reliability of an Analytical Information System

“…Therefore, the study of issues related to natural gas, such as its extraction and transmission, has been the focus of many researchers. Also, the design, construction, and optimization of its storage tanks for different purposes have been considered, because these tanks are at risk of bursting and exploding [1][2][3]. In addition to the above-mentioned cases, the quality of natural gas is also important and can significantly affect the efficiency of the system and the quality of the final product.…”

Effect of Corrosive Environment on the High-Cycle Fatigue Behavior of Reinforced Concrete by Epoxy Resin: Experimental Study

“…Here, the subject of fatigue-corrosion is one of the most complex phenomena, which is very difficult and, in some cases, impossible to test in accordance with reality. On the other hand, the development of science and simulation software has made it possible to study the behavior of complex systems with a little simplification and at a much cheaper cost than performing tests [28]. For example, in the field of investigating the behavior of concrete, Song et al presented a new finite element (FE) model based on three-dimensional particles to estimate the lifetime of concrete under compression cyclic loading [29].…”