Ballistic penetration damages and energy absorptions of stacked cross-plied composite fabrics and laminated panels

2020 ◽  
Vol 29 (9) ◽  
pp. 1465-1484
Author(s):  
Qingsong Wei ◽  
Bohong Gu ◽  
Baozhong Sun

Flexible fabrics have been widely used in body armor designs. Here we report ballistic impact damage of stacked cross-plied composite fabric and cross-plied laminated panels. The ballistic impact behaviors of stacked cross-plied composite fabric and cross-plied laminated panel have been tested with fragment-simulating projectiles under the strike velocity 550–600 m/s to explore the influence of the layers combination of fabric target on ballistic impact. Two types of macroscopic anisotropy continua finite element models based on fabric targets structures are established to analyze the ballistic mechanism of stacked cross-plied composite fabric and cross-plied laminated panels. The impact damage morphologies and energy absorptions have also been compared between the tests and finite element analysis results. We have found the stacked fabric construction absorbed more energy than their counterpart cross-plied laminated panel, while the laminated panel shows better structural integrity and stability during ballistic penetration.

2015 ◽  
Vol 12 (19) ◽  
pp. 5871-5883 ◽  
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.


2010 ◽  
Vol 45 (9) ◽  
pp. 965-987 ◽  
Author(s):  
Xiwen Jia ◽  
Baozhong Sun ◽  
Bohong Gu

Ballistic penetration of conically cylindrical steel projectile into 3D orthogonal woven composite (3DOWC) was investigated from finite element analyses and ballistic impact tests. Based on the observation of the microstructure of the 3DOWC, a microstructure model was established for finite element calculation. In this model, the cross-section of warp, weft and Z-direction fiber tows was regarded as rectangular. The noninterwoven warp and weft yarns were bonded together with Z-yarns. The impact damage and energy absorption of the 3DOWC penetrated by a conically cylindrical steel projectile were calculated from the microstructure model and compared with the testing results. Good agreements with experiments have been observed, especially for deformation, damage evolution, and strain wave distribution in the 3DOWC under ballistic penetration.


2008 ◽  
Author(s):  
Fuqiang Wu ◽  
Frank Puskar ◽  
Pascinthe Saad

Concrete Gravity Based Structure (GBS) provides an opportunity for the storage of Liquefied Natural Gas (LNG) and represents one of the key elements of an LNG receiving and regasification terminal. The impact resistance of an offshore LNG GBS against accidental ship collision needs to be evaluated. Nonlinear elasto-plastic Finite Element Analysis (FEA) provides a useful numerical tool to assess the damage and evaluate the overall structural integrity of the GBS following a ship collision. In the work presented, a large capacity tanker was modeled using FEA and simulated to collide into a prototype concrete LNG GBS. An efficient, two-step approach was applied to estimate the damage levels caused by the striking tanker considering different approach speeds. Various benchmark tests were conducted to validate the steel and concrete FEA models to ensure the reliability of the analysis. The simulation shows that certain collisions can cause damage to both the tanker bow and the LNG GBS, depending upon the collision speed and the configuration of the colliding bodies. However, these collisions do not always result in a breach of the LNG containment. The results of this type of assessment can be used to assist in designing the LNG GBS to improve its impact resistance. The results can also be used in risk studies typical of these types of facilities.


Author(s):  
Mingquan Long

In order to study the three jump training and competition on knee joint impact damage degree, left knee joint of one healthy male athletes is used as the research object, a complete knee three-dimensional model was established based on the jumper’s knee CT scan and magnetic resonance imaging (MRI), including the femur, tibia, fibula, patella and knee major cartilage, ligaments. The multi-body dynamics analysis (MDA) and finite element analysis (FEA) method are used to calculate the three jump, jump starting, landing process of athletes knee joint impact, the state should change the status of stress, strain and displacement. The results show that in the three jump process, the load on the lateral contact area of the knee joint is the largest, the displacement is the largest, and it increases with the impact of jump and landing. This exacerbated the degree of wear and tear of the tibia, it tends to induce knee injury in athletes. The results show that the combination of finite element and MDA can better study the knee joint’s shock and vibration during the three-level jump training and competition, and these open up a new research method for the knee joint injury. It also provides a certain reference for the prevention and treatment of knee joint injury.


2018 ◽  
Vol 48 (6) ◽  
pp. 1044-1058 ◽  
Author(s):  
Pibo Ma ◽  
Limin Jin ◽  
Liwei Wu

This paper compares the ballistic impact damage behaviors between the three-dimensional angle-interlock woven fabric and its reinforced composite (three-dimensional angle interlock woven composite) under various ballistic strike velocities based on experimental and numerical finite element analysis. In experiments, the residual velocities of projectiles were recorded to compare their ballistic proof properties undergoing different impact loading conditions. Furthermore, the ultimate damage morphologies of both types of materials were also compared to deduce the specific ballistic impact performance and energy absorption mechanisms between the three-dimensional angle interlock woven fabric and three-dimensional angle interlock woven composite. It was found that the three-dimensional angle interlock woven composite has absorbed more energy than the three-dimensional angle interlock woven fabric under the “high” ballistic velocities (higher than 350 m/s). And it shows the opposite phenomena under the “low” ballistic velocities (lower than 350 m/s). In finite element analysis, the simplified finite element models were established for both materials to characterize the critical importance of resin matrix in transferring and dissipating the high velocity impact energy. Especially for three-dimensional angle interlock woven composite, the impact energy was transferred to the large area during a relatively short period of time, thereby resulting in an overall bearing capacity of the composite structure, therefore absorbed most of the impact energy, which was well applied to explain the experimental results.


2007 ◽  
Vol 334-335 ◽  
pp. 485-488 ◽  
Author(s):  
Jun Lian ◽  
Bo Hong Gu ◽  
Wei Dong Gao

This paper presents a real microstructure model which has the same fiber volume fraction and tows’ spatial configuration with 3D rectangular composites to simulate the ballistic impact damage of the composites struck by steel projectile. The commercial available FEM code of Ls-Dyna was employed to calculate the interaction between the composite targets and steel projectile. From the comparison of residual velocities between simulation and experiment, it is proven the microstructure model can simulate the ballistic penetration with higher precision than the continuum model. The acceleration vs. time curve reveals the complicated interaction between composite and projectile in ballistic penetration. The prominent advantage of the microstructure model is that it can simulate the local damage mode of the composites at real microstructure level and obtain vivid simulating results.


2015 ◽  
Vol 12 (4) ◽  
pp. 3855-3877
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focussed on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA), suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE-models that represent coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasizing the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.


1998 ◽  
Vol 26 (1) ◽  
pp. 51-62
Author(s):  
A. L. A. Costa ◽  
M. Natalini ◽  
M. F. Inglese ◽  
O. A. M. Xavier

Abstract Because the structural integrity of brake systems and tires can be related to the temperature, this work proposes a transient heat transfer finite element analysis (FEA) model to study the overheating in drum brake systems used in trucks and urban buses. To understand the mechanics of overheating, some constructive variants have been modeled regarding the assemblage: brake, rims, and tires. The model simultaneously studies the thermal energy generated by brakes and tires and how the heat is transferred and dissipated by conduction, convection, and radiation. The simulated FEA data and the experimental temperature profiles measured with thermocouples have been compared giving good correlation.


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