scholarly journals Numerical simulation on Crashworthiness of 105000t LNG Carrier

2021 ◽  
Vol 2083 (3) ◽  
pp. 032037
Author(s):  
Qian Sun ◽  
Jianmin Liu ◽  
Hong Zhou
Keyword(s):  
Numerical Simulation ◽  
Impact Damage ◽  
Impact Angle ◽  
Practical Significance ◽  
Structural Repair ◽  
Impact Location ◽  
Force Velocity ◽  
Finite Element Numerical Simulation ◽  
Bulbous Bow ◽  
The Impact

Abstract It is of great significance to study the crashworthiness of LNG carrier to improve its crashresistance and enhance its operation safety. In this paper, the collision process between the bulbous bow of the container ship and the side structure of the LNG ship is analyzed by using nonlinear finite element numerical simulation. Collision performance of LNG carrier and collision indicators during the collision, the impact force, velocity and displacement and energy absorption in the process of collision by changing parameters of the major velocity, impact angle and impact location and others are studied. The relevant research results have a strong practical significance for analyzing the deformation, strengthening measures and structural repair of ship side structure impact damage.

scholarly journals Numerical Investigation on the Ultimate Strength of Box Beams with Impact Damage

2020 ◽  
Author(s):  
Wei Xu ◽  
C. Guedes Soares
Keyword(s):  
Residual Stress ◽  
Ultimate Strength ◽  
Impact Damage ◽  
Ship Hulls ◽  
Four Point Bending ◽  
Impact Location ◽  
Box Beam ◽  
Box Beams ◽  
Fracture Damage ◽  
The Impact

AbstractThe objective of this paper is to study the residual ultimate strength of box beams with impact-induced damage, as a model of what may occur in ship hulls. The bottom and side plates of ship hulls can suffer denting or fracture damage due to grounding, collision and other contacts during the ship’s service life and these impact-induced damages could result in considerable strength degradation. Box beams are firstly subjected to impact loading and then four-point bending loading is imposed on the damaged structures to assess the residual strength using ANSYS/LS_DYNA. The ultimate moment and collapse modes are discussed considering the effect of impact location. The impact-induced deformation is introduced in the four-point bending simulation, and the impact-induced stress is included or not to determine the effect of residual stress and distortion after impact. It is shown that impact location has significant influence on the residual ultimate bending moment of the damaged box beam providing that the impact energy is kept constant. The collapse modes also change when the impactor strikes on different locations. Damaged hard corner and inclined neutral axes might explain the reduction of ultimate strength and diverse collapse modes. The residual stress in the box beam after impact may increase or decrease the ultimate strength depending on impact location.

Numerical Simulation of a Dilute Particulate Flow (Laminar) Over Tube Banks

1994 ◽  
Vol 116 (4) ◽  
pp. 770-777 ◽  
Author(s):  
Yong-Du Jun ◽  
Widen Tabakoff
Keyword(s):  
Numerical Simulation ◽  
Impact Angle ◽  
Protective Role ◽  
Point Of View ◽  
Particulate Flow ◽  
Tube Bank ◽  
Semiempirical Equation ◽  
Tube Banks ◽  
Bank System ◽  
The Impact

This paper presents an investigation of numerical simulation for a dilute particle laden flow (laminar) over in-line tube banks. Particles behavior of two different sizes and density (100 μm sand and 40 μm fly ash) is demonstrated through the present study for a fixed geometry and flow condition, that is, a square in-line tube bank of two rows deep with pitch-to-diameter ratio of two at Reynolds number 400. Dilute particulate flow assumption is used and the drag force is considered as the only external force term that affects the particles behavior in the flow. Experimental rebounding data and semiempirical equation for the erosion estimation are used. It was found through the present simulation that the particles behavior of the different sizes and density in tube bank system is quite different in their trajectories, impact and the erosion pattern. The protective role of the first row of cylinders could be supported with respect to the particles collision on the cylinder but not necessarily to the erosion point of view. Also the information at impact such as the impact velocity and the impact angle which affect the erosion (Tabakoff et al., 1988) can be estimated by using the numerical simulation shown in the present study.

scholarly journals Low-speed impact damage analysis of aviation composite material structure

2021 ◽  
Vol 260 ◽  
pp. 03021
Author(s):  
Jun He ◽  
Meng Cao ◽  
Zhishu Wang ◽  
Fanglin Cong
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Composite Material ◽  
Composite Structures ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Material Structure ◽  
Damage Analysis ◽  
Low Speed ◽  
The Impact

Although the carbon fiber reinforced composite material has high specific strength and stiffness, design-versatility, anti-corrosion and other excellent features, but the impact resistance of composite structures is poor. Therefore, the composite laminates low-speed damage analysis has important significance. Based on a three-dimensional analysis theory of cumulative damage, using the commercial finite element analysis software ABAQUS to establish laminates subjected to low velocity impact finite element model. according to the numerical results and the consistency of the test results, shows that the used model of the article is reasonable and accurate, and the numerical simulation method is verified to be feasible. Finally, through the numerical simulation of process of laminated plates low speed impact damage, the damage characteristics and damage mechanism of the laminates at different times are analyzed, and the forming reasons and expanding rules of the main damage forms of fiber damage and matrix damage are revealed.

Some Issues in Passive Impact Location Detection Triangulation in Composite Materials Using Embedded Piezoelectric Sensors

2012 ◽  
Author(s):  
Bruno Zamorano-Senderos ◽  
Niell Elvin ◽  
Samuel Shin
Keyword(s):  
Evaluation Method ◽  
Residual Life ◽  
Impact Damage ◽  
Computational Cost ◽  
Piezoelectric Sensors ◽  
New Technique ◽  
Impact Location ◽  
Location Detection ◽  
Extent Of Damage ◽  
The Impact

This paper studies some aspects of impact location detection in composites materials using triangulation methods with embedded piezoelectric sensors. The first step of any impact damage evaluation method is to ascertain if an impact has happened and its location. More sophisticated methods (not addressed in this paper) can then be used to determine the type and extent of damage and to estimate the residual life of the structure. We propose a novel sensor array that potentially reduces the number of computations required to locate the position of the impact and reduces the complexity of embedded sensor wiring. Reducing the computational complexity allows the use of lighter, cheaper and less energy consuming electronic devices. The new technique reduces the classical computation from a planar (two dimensional) search to an angular (one dimensional) search. The new technique is experimentally compared with a classical triangulation technique at moderate ballistic speeds (300 m/s). This paper shows that the new technique reduces the computational cost, but also reduces accuracy of impact location.

scholarly journals EXPERIMENT ON IMPACT DAMAGE OF CASTOR CAPSULE AND ITS INFLUENCING FACTORS OPTIMIZATION

2020 ◽  
Vol 61 (2) ◽  
pp. 87-96 ◽  
Author(s):  
Junming Hou ◽  
Yong Yang ◽  
Hongjie Zhu ◽  
Weixue Hu
Keyword(s):  
Water Content ◽  
Impact Force ◽  
Impact Damage ◽  
Impact Angle ◽  
Maximum Deformation ◽  
Combination Optimization ◽  
Damage Degree ◽  
Castor Seeds ◽  
Maximum Impact Force ◽  
The Impact

Castor is an important oil crop. Impact damage is critical in the process of castor capsule shelling, directly affecting the shelling effect of castor seeds. An experiment was taken to investigate it. To study the damage degree of castor capsule under the impact, water content, impact height, and impact angle were taken as test factors, and the maximum impact force and normal deformation were taken as test indexes. The combination optimization was carried out through the multi-objective genetic algorithm. The results show that the impact height has a significant effect on the maximum deformation (p<=0.01), and the water content and impact angle have a significant impact on the impact force (p<=0.05). The height and angle have a significant impact on the deformation (p<=0.01), and the water content has a significant impact on the deformation (p<=0.05).

The Effect of Impact Angle and Fall Height on Skull Fracture Patterns in Infants

2021 ◽  
Vol 143 (7) ◽  
Author(s):  
Jiawei Yan ◽  
Junyan He ◽  
Ashely Spear ◽  
Brittany Coats
Keyword(s):  
Skull Fracture ◽  
Fracture Initiation ◽  
Initiation Site ◽  
Impact Angle ◽  
Fracture Length ◽  
Fracture Initiation Site ◽  
Impact Location ◽  
Fracture Patterns ◽  
The Impact ◽  
Fall Height

Abstract Skull fracture is a common finding for both accidental and abusive head trauma in infants and young children, and may provide important clues as to the energy and directionality of the event leading to the skull fracture. However, little is understood regarding the mechanics of skull fracture in the pediatric skull, and how accidental fall parameters contribute to skull fracture patterns. The objectives of this research were to utilize a newly developed linear elastic fracture mechanics finite element model of infant skull fracture to investigate the effect of impact angle and fall height on the predictions of skull fracture patterns in infants. Nine impact angles of right parietal bone impacts were simulated from three different heights onto a rigid plate. The average ± standard deviation of the distance between the impact location and fracture initiation site was 8.0 ± 5.9 mm. Impact angle significantly affected the fracture initiation site (p &lt; 0.0001) and orientation (p &lt; 0.0001). A 15 deg variation in impact angle changed the initiation site up to 47 mm. The orientation of the fracture pattern was dependent on the impact location and ran either horizontal or vertical toward the ossification center of the bone. Fall height significantly affected the fracture length (p = 0.0356). Specifically, at the same impact angle, a 0.3 m increase in fall height increased the skull fracture length by 21.39 ± 34.26 mm. These data indicate that environmental variability needs to be carefully considered when evaluating infant skull fracture patterns from low-height falls.

Numerical Simulation of Hypervelocity Impact on Mesh Bumper Causing Fragmentation and Ejection

2012 ◽  
Vol 525-526 ◽  
pp. 401-404
Author(s):  
Gong Shun Guan ◽  
Rui Tao Niu
Keyword(s):  
Numerical Simulation ◽  
Kinetic Energy ◽  
Impact Angle ◽  
Hypervelocity Impact ◽  
Impact Position ◽  
Debris Cloud ◽  
Combination Mode ◽  
The Impact ◽  
The Relationship ◽  
Aluminum Mesh

In order to study the fragmentation of projectile and ejection of debris clouds caused by hypervelocity impacting mesh bumper, simulation of aluminum sphere projectile hypervelocity normal impacting aluminum mesh bumper was practiced with SPH arithmetic of LS-DYNA soft. The diameter of projectile was 4mm. Impact velocities of aluminum spheres were varied between 2.2km/s and 6.2km/s. The impact angle was 0°. The relationship between the debris clouds characteristic of projectile and the impact position on aluminum mesh bumper was studied. The effect on fragmentation of projectile from different combination mode of aluminum mesh bumper was analyzed. The results showed that the morphologies of the debris cloud varied with the impact position when a projectile impacted the mesh bumper. The debris clouds as palpus was found, and some local kinetic energy concentrated appeared in the debris clouds. Debris clouds distribution was more uniform when projectile impacted wire across point on the mesh bumper. Debris clouds had more diffuse area and less residual kinetic energy when mesh bumper was combined with interleaving mode. Mesh bumper combined with interleaving mode was helpful in enhancing the protection performance of shields.

Experimental study on the high-speed impact of a sand particle on Ti–6Al–4V

2019 ◽  
Vol 234 (4) ◽  
pp. 632-646
Author(s):  
Cheng Yan ◽  
Wei Chen ◽  
Zhenhua Zhao
Keyword(s):  
High Speed ◽  
Impact Damage ◽  
Damage Mechanism ◽  
Impact Angle ◽  
Sand Particle ◽  
Compressor Blades ◽  
Supersonic Airflow ◽  
High Speed Impact ◽  
Sand Particles ◽  
The Impact

When sand is ingested by a helicopter engine, it collides with the compressor blades at a high relative speed, causing severe erosion damage. A test was conducted on the high-speed impact of sand particles on the target of Ti–6Al–4 V alloy to enhance the understanding of high-speed impact damage mechanism. The test apparatus was used to create supersonic airflow, which was produced by normal temperature air flowing through a special Laval nozzle. The supersonic airflow produced the drag force to increase the velocity of sand particles up to about 400 m/s. The experiment demonstrated that fractured sand particle caused less damage than nonfractured particle under similar impact conditions. The nonfractured particle directly cut the target more easily than the fractured at a relatively low impact velocity. When the impact speed exceeded 300 m/s, the crater depth increased exponentially with the increase of velocity. Impact angle determined the mode of material failure.

EFFECTS OF IMPACT LOCATION AND ANGLE OF A FLYING CROSS BAR ON THE PROTECTION OF A LONG-ROD PENETRATOR

2013 ◽  
Vol 37 (4) ◽  
pp. 1115-1125 ◽  
Author(s):  
Yo-Han Yoo ◽  
Seung Hoon Paik ◽  
Jong-Bong Kim ◽  
Hyunho Shin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Impact Angle ◽  
Element Analysis ◽  
Impact Location ◽  
Long Rod ◽  
The Impact ◽  
Bar Diameter

Based on a finite element analysis, the performance of a flying cross bar in protecting a long-rod penetrator increases as the impact location moves toward the head of the penetrator. It also increases as the impact angle approaches right angle. The optimal impact location along the span direction of the bar varies depending on the bar diameter.

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