Numerical Evaluation on Lateral Impact Resistance of Thermoplastic Composite Pipes in Terms of Internal Pressure Capacity

Author(s):  
J. Wang ◽  
C. Shi ◽  
G. Fu ◽  
Z. Liu ◽  
X. Bao ◽  
...  

Abstract Subsea pipelines are prone to be damaged by the falling objects from ships or offshore platforms, which may result in economic losses and pollution. The dimensions of dent were commonly used to evaluate the impact resistance of pipes made from carbon steel. Thermoplastic composite pipes (TCPs), due to their superior properties including corrosion resistance, thermal insulation, fast installation, etc., are increasingly used as the subsea pipelines. The TCP is made from thermoplastic resins and reinforced by continuous fibers. Because of the brittle nature of carbon fibers and glass fibers, the dimensions of dent are not suitable for assessment of impact resistance of a TCP. In the present work, a procedure was proposed using the internal pressure capacity as an indicator to evaluate the lateral impact resistance of a TCP. First, the internal pressure capacity of an intact TCP was evaluated. Second, a quasi-static simulation was conducted by applying a lateral compression force on the intact TCP using a rigid ball, until one of the composite plies in the reinforcement layer failed. The quasi-static simulation provided an initial estimate of the minimum energy that causes the start of damage of the TCP. Third, the impact simulations were performed by using a rigid ball hitting the TCP and, then, the internal pressure capacity of the damaged TCP was evaluated. Finally, the internal pressure capacity of the damaged pipe, compared with that of the intact pipe, was used as an indicator to evaluate the lateral impact resistance of the TCP. In this study, a glass-fiber reinforced polyethylene (PE) pipe of an inner diameter of 150 mm was modeled by ABAQUS to illustrate the procedure. A theoretical method was proposed to calculate the impact energy of a dropped object in a shallow water. The example studied in the present work showed that the modeled TCP was not strong enough to survive the lateral impact caused by the dropped object and should be buried to a certain depth beneath the seabed if used as a subsea pipeline.

2021 ◽  
Author(s):  
Heping Xia ◽  
Chen Shi ◽  
Jialu Wang ◽  
Xingxian Bao ◽  
Hongwei Li ◽  
...  

Author(s):  
H. Xia ◽  
C. Shi ◽  
J. Wang ◽  
X. Bao ◽  
H. Li ◽  
...  

Abstract Thermoplastic composite pipes (TCPs) are increasingly used to transport hydrocarbons and water in the oil and gas industry due to their superior properties including corrosion resistance, thermal insulation, light weight, etc. The cross-section of TCPs generally consists of three layers: inner liner, composite laminate, and outer jacket. Three layers are bonded together and form a solid-wall construction. Inner liner and outer jacket made of thermoplastic polymer provide protective barriers for the laminate to against the inner fluid and outer environment. The laminate is constructed by an even number of helically wounded continuous fiber reinforced thermoplastic composite tapes. In this study, mechanical behaviors of a TCP under an internal pressure were investigated by using analytical and finite element analysis (FEA) methods. The analytical method which is based on the three-dimensional (3D) anisotropy elastic theory can take account of non-uniformly distributed stress and strain through the thickness of the pipe wall. FEA models were setup by using the software ABAQUS to predict the stress distribution of the pipe. 3D Tsai-Wu failure criterion was used to predict the maximum internal pressure of the pipe. Effects of some critical parameters, such as the winding angle of composite tapes and the number of reinforced plies, on the internal pressure capacity of TCPs were studied. Results obtained from the analytical and FEA methods were fairly agreed with each other, which showed that with the increasing of the number of reinforced plies the internal pressure capacity of a TCP gradually increases and approaches to an extreme value. In addition, the optimal winding angle which results the maximum internal pressure is not a constant value, instead, it varies with the increasing thickness of the laminate layer. This study provides useful tools and guidance for the design and analysis of TCPs, and is currently under validation through experiments.


Author(s):  
Yangqing Dou ◽  
Yucheng Liu

This paper provides a combined computational and analytical study to investigate the lateral impact behavior of pressurized pipelines and inspect all the parameters such as the outside diameter and internal pressure affects such behavior. In this study, quartic polynomial functions are applied to formulate the maximum crushing force (F), maximum permanent displacement (W), and absorbed energy (E) of the pressurized pipelines during the impact problem. The effects of the diameter and pressure on F, W, and E are therefore illustrated through analyzing those functions. Response surfaces are also plotted based on the generated quartic polynomial functions and the quality (accuracy) of those functions are verified through several techniques.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yongzheng Wu ◽  
Yukai Fu ◽  
Denyun Hao ◽  
Gangye Guo

In order to reveal the impact mechanical properties and their key influencing factors of the bolted rock under the lateral impact load, through the lateral drop hammer impact test, the time-history curve of impact force, axial force of the bolt, and surface strain of the sample under different combination types of influencing factors is obtained, and the whole process of deformation and failure of the bolted rock is recorded. The test results show that the material of the bolt has a significant influence on the impact force and axial force of the bolt. There is a positive correlation between bolt strength and impact peak and impact attenuation slope and a negative correlation between bolt strength and impact action time. The effect of prestress on the impact resistance of the bolted rock was also evaluated by the test which suggested that prestress of the bolt can significantly reduce both impact time and bolt axial force of the bolted rock but has limited effect on the impact force. It was also found that the time-history curve of the impact force of anchoring rock mass had significant difference with full-length anchoring and nonanchoring. Compared with the nonanchoring bolt, the full-length anchored rock mass has a larger impact peak and shorter action time, which means that the impact resistance of the full-length bolted rock has a certain degree of weakening. Through scientific research, determining the reasonable bolt material, prestress value, and anchorage style can improve the impact resistance of the sample.


2018 ◽  
Vol 18 (07) ◽  
pp. 1850089 ◽  
Author(s):  
Naseer H. Farhood ◽  
Saravanan Karuppanan ◽  
Hamdan H. Ya ◽  
Mark Ovinis

In this study, the impact damage resistance of carbon/basalt hybrid fiber reinforced polymer pipes was experimentally investigated under low velocity impact loading. The composite pipes, composed of thin plastic liner of HDPE wrapped with eight layers of plies at constant winding angle of [[Formula: see text]55[Formula: see text]/90[Formula: see text]/[Formula: see text]55[Formula: see text]/90[Formula: see text]], were fabricated through filament winding technique. Eight pipe configurations with different stacking sequence and fiber content proportion were studied. Specimens cut from the original pipes were tested in a drop weight impact machine under two levels of impact energies, 50[Formula: see text]J and 100[Formula: see text]J, in order to predict the impact response and induced damage resistance of the pipe. The damage of the tested pipes was assessed based on the force-displacement, force-time histories, the energy absorption mechanism, as well as the micrographs captured by scanning electron microscope (SEM) for the specimens. The results indicate that the impact resistance behavior was highly affected by the stacking sequence of the layers and partly affected by the fiber content ratio. Positioning the basalt fiber on the impacted side enhances the energy absorption mechanism for both levels of imposed energies, while improving the impact resistance. The addition of 50% basalt fiber can slightly increase the impact resistance compared to the addition of 25% basalt fiber. However, specimens with 25% basalt fiber showed lower peak force, lower damage area and lower energy absorption.


Author(s):  
Zheng Luo ◽  
Wang Yinhui

The pendulum impact tests were carried out on one RC frame column and four RC free-standing columns. The effect of axial compression ratio and reinforcement ratio on the impact resistance of columns were compared by means of dynamic time curves of framed and freestanding columns under impact. The test results show that with the same impact load, though the presence of axial loads can play a positive role (e.g., reducing the residual displacement), it may lead to more severe local damage. Also, compared with free-standing columns, the frame column can be considered as a protective structure for its greater lateral stiffness and stronger crashworthiness. The corresponding finite element models are developed,and the influence of the axial loads on cross section force responses under impact excitation is deeply explored. The axial loads can significantly affect the distribution of the moment, the shear force, and also the damage for the column.


Author(s):  
Yi Wang ◽  
Jixiang Yue ◽  
Menglan Duan ◽  
Zhang Yu ◽  
Yi Zhao

Subsea pipelines have been widely used to transfer oil from platforms to the mainland near harbor anchorage zone, and they become increasingly susceptible to risks stemming from dropped object impact damages. The impact from dropped objects may lead to local deformation and fracture in the pipeline and vast economic and environmental consequences. In this research, the responses of continuously supported offshore pipelines subjected to transverse impacts caused by dropped objects are studied. For this, the impact on an internally pressurized pipeline resting on a flexible bed has been numerically simulated. A relatively extensive parametric study has then been carried out to examine effects from variations in the cement coating thickness, internal pressure, indenter shape, impact velocity and subsoil mechanical properties on the pipeline response. It has been noticed that the presence of internal pressure results in substantial decrease in the impact dent depth, causing the deformation to become spatially more localized. It has also been shown that the flexibility of pipe bed plays an important role in the impact energy dissipation.


Author(s):  
Nayyer Mohammadi Rana ◽  
Elham Ghandi ◽  
Shirin Esmaeili Niari

In recent years, the use of partially concrete-filled steel tubular (PCFST) columns has been considered due to their cost-effectiveness and reduction of structural weight in bridge piers and building columns. One of the critical discussions about these columns is their impact resistance. In this article, the dynamic response of hollow and PCFST columns with elliptical cross-section under simultaneous loading of static axial compressive load and lateral impact load is presented using finite element modeling in ABAQUS software (FEA). To ensure the accuracy of the numerical modeling, the analysis results are compared with the results of previous works. The effects of different parameters such as impact velocity, the height of the impact location, the impact direction, the impact block mass, the size and shape of the impact block are investigated in this paper. The results of the numerical analysis showed that the partially filled specimens had better performance than the hollow specimens. The changes in impact direction and impact block mass parameters have a significant effect on the failure of the columns, especially when they are under high impact velocity. Changing the impact velocity significantly affects the impact resistance of specimens. However, the size and shape of the impact block did not have a significant effect on the displacement of the column against the impact loading.


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