Numerical Study on Plastic Strain Distributions and Mechanical Behaviour of a Tube under Bending

Tubular pipe structures have been used in various applications—domestic, aviation, marine, manufacturing and material testing. The applications of tubular pipes have been considered greatly in the installation of tubular pipes, marine risers and pipe bending. For the investigation of plastic strains and the mechanical behaviour of a tube under bending, considerations were made utilising an exponent model with assumptions on the plane strain. The bending moment, wall thickness effect, cross-sectional distribution, stresses during bending and neutral layer boundaries were all presented as necessary theoretical formulations on the physics of tubular pipe bending. This model was based on the analytical and numerical investigation. In principle, the application can be observed as the spooling of pipes, bending of pipes and reeling. Comparisons were made on two models developed on the finite element analysis in Simscale OpenFEA, namely the linear-elastic and the elasto-plastic models. This study presents visualization profiles using plastic strain to assess its effect on the tubular pipes. This can increase due to the limitation of plastic deformation on the composite materials selected.

Propagation Characteristics of Pressure Pulsation in Hydraulic Hose

Most modern aircraft hydraulic systems use variable plunger pumps. The pulsating flow output is its inherent characteristic. The resulting pressure pulsation often causes serious damage to the energy pipeline system and endangers the lives of the occupants. This paper studies the propagation law of hydraulic oil in hydraulic hoses, fully considers the coupling vibration of hydraulic oil high-pressure fluid and flexible solids of the hose, establishes a fluid-solid coupling vibration model of hydraulic hoses, and uses ANSYS for numerical simulation to study different frequencies and pipe bending. Using ANSYS for numerical simulation to study the influence of different frequencies and pipe bending radii on the amplitude of fluid pressure pulsation, after comparative analysis, the law of fluid pressure pulsation propagation in hydraulic hoses is obtained.

Hydraulic Pipe Bending Machine

The process of pipe bending finds its importance in many industries, instruments, fluids transportation etc. The aim of this research is to design and fabricate a hydraulic jack-based pipe bending machine which has ability to bend pipes used at gas supply industry, while keeping in mind the requirements of a good pipe bending machine to provide high quality bends without defects but at the cost lesser than the existing pipe bending machines available in the marketplace. The fabricated pipe bending machine works on the principle of press bending method to perform the bending operation. The design of the proposed pipe bending machine is based on essential parameters of bending process such as radius and angle of the bend, diameter and thickness of the pipe. The single acting hydraulic jack of 16000 KG load capacity is used to apply the required pressing force to bend a circular pipe having the outer diameter ranging from ½ inch to 2 inches.

Design of Manual Pipe Bending Mechanism

Rotary draw bending an ongoing process. It’s an at-hand service proffered within the current market. However, each draw bender features a divergent mechanism with its pros and cons, thanks to its main advantages; the rotary draw bender was selected. Pipe bending machines have progressed many enhancements and augmentations over the amount. The sort of pipe bending plays a critical role in industries, instruments, and transporting of fluids. The first concern is that the required bend angle that this pipe will bend on. The following report will include an outline of the accessibility of this machine. The crucial variables that ought to be accounted for within the pipe bending is bend radius bend angle, pipe diameter, and thickness. The concept of press bending is employed to hold out the operation; thus, the specified force is administered with the help of a hydraulic jack. Also, other important variables are accounted for, like the bending force, bending torque, simulation outcomes about the work piece analysis, and eventually the machine design. Moreover, a prototype that satisfies the specified constraints is manufactured and assembled. Being a manual bending machine means no use of electricity is required, leading to no power consumption. Additionally, this machine is favorable, feasible, affordable, low maintenance, and higher accuracy.

Research on the Bearing Capacity of a Damaged Jacket Repaired by a Grouting Clamp Based on a Type of Wedge Gripping

In the process of repairing a damaged jacket with a grouting clamp, it is necessary to analyze the bearing capacity of the damaged structure to determine whether it meets requirements for maintenance and reinforcement. On the basis of previous research results, this paper proposes a design scheme of a grouting clamp based on wedge gripping, which can effectively improve the local bearing capacity of the jacket by more than 35%. The elastic–plastic theory was used to analyze the bearing capacities of steel pipe piles under three different conditions (ideal steel pipe, bending steel pipe and steel pipe with a defective section) and with reinforcement by a grouting hoop. The bearing capacity of the mechanical grouting clamp was analyzed, and the resulting theoretical design was verified by a bearing performance experiment. The results support the conclusion that the wedge mechanical grouting clamp can effectively strengthen local jacket members.

Plastic-yielding analysis in the pipe-bending process of AZ31 and AA7050 using the normalized Cockcroft and Latham criterion

Compared with other sheet-metal-forming processes, the deformation conditions of pipe bending are affected by the material, equipment, die, and multiple other factors. Therefore, it is urgent to explore methods that avoid forming defects and improve the bend-forming quality. Wall-thinning induced ductile fracture is one of the dominant defects in the pipe-bending process, especially for materials with lower ductility. In this study, the normalized Cockcroft and Latham criterion is embedded into the user subroutine USDFLD within the Abaqus finite element (FE) software to predict the fracture tendency of a bent pipe. Through a comparison of theoretical calculations and simulation results, a simplified FE model of rotary draw bending was established, and the damage evolution and distribution of bent pipes composed of AZ31 and AA7050 materials were investigated. The results show that the two materials have similar regularity, and damage mainly generates and accumulates in the outer surface of the deformation zone due to wall thinning. The damage value remains at a certain level after the bending deformation enters the stable stage. This study provides a concept and strategy for more efficiently predicting the fracture tendency of a bent pipe.