Comparison of Detailed Sagittal and Transverse Finite Element Head Models to Evaluate Blast Load Response

2011 ◽  
Author(s):  
Dilaver Singh ◽  
Philip A. Lockhart ◽  
Tyler N. Haladuick ◽  
Duane S. Cronin
Keyword(s):  
Finite Element ◽  
Blast Load ◽  
Load Response ◽  
Finite Element Head Models

Finite Element Analysis on the Blast Resistant Performance of Multibarrel Tube-Confined Concrete Column in Different Cross-Sections

2013 ◽  
Vol 721 ◽  
pp. 545-550
Author(s):  
Sai Wu ◽  
Jun Hai Zhao ◽  
Er Gang Xiong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Detonation Wave ◽  
Cross Section ◽  
Cross Sections ◽  
Failure Modes ◽  
Circular Cross Section ◽  
Blast Load ◽  
Element Analysis ◽  
The Impact

Based on the finite element analysis software ANSYS/LS-DYNA, this paper numerically analyzed the dynamic performance of MTCCCs with different cross sections under blast load, followed by the study and comparison on the differences of the detonation wave propagation and failure modes between the columns in circular cross section and square cross section. The results show: The blast resistant performance of the circular component is more superior than the square component for its better aerodynamic shape that can greatly reduce the impact of the detonation wave on the column; The main difference of the failure modes between the circular and square cross-sectional components under blast load lies in the different failure mode of the outer steel tube. The simulation results in this paper can provide some references for the blast resisting design of MTCCCs.

scholarly journals Numerical Simulation of Blast Loaded CFRP Retrofitted Steel Plates

2021 ◽  
Vol 347 ◽  
pp. 00038
Author(s):  
Mujtaba M. Shuaib ◽  
Steeve Chung Kim Yuen ◽  
Gerald N. Nurick
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Structural Response ◽  
Steel Plates ◽  
Blast Load ◽  
Cylindrical Charge ◽  
Arbitrary Lagrangian Eulerian ◽  
Finite Element Software ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

This paper reports on the results of a numerical study to simulate the response of carbon fibre reinforced polymer (CFRP) retrofitted steel plates to applied blast loads using finite element software, LS-DYNA. The results of the simulation were validated against plate response and magnitude of deformation obtained from previous experiments. The uniform blast load was generated in the experiment by detonating a cylindrical charge down the end of a square tube. The finite element code LS-DYNA was used to simulate the structural response of the respective blast structures. For the numerical model, the blast load was simulated using the mapping feature available in LS-DYNA for the multi-material arbitrary Lagrangian-Eulerian (MM-ALE) elements which significantly reduced the size of the air domain in the model. The simulations showed a satisfactory correlation with the experiments for the blast results and post-failure deformations that occurred in CFRP retrofitted steel plates.

scholarly journals Development of a Knee Joint CT-FEM Model in Load Response of the Stance Phase During Walking Using Muscle Exertion, Motion Analysis, and Ground Reaction Force Data

Medicina ◽  
2020 ◽  
Vol 56 (2) ◽  
pp. 56
Author(s):  
Kunihiro Watanabe ◽  
Hirotaka Mutsuzaki ◽  
Takashi Fukaya ◽  
Toshiyuki Aoyama ◽  
Syuichi Nakajima ◽  
...  
Keyword(s):  
Finite Element ◽  
Knee Joint ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Equivalent Stress ◽  
Element Model ◽  
Calculation Model ◽  
Quantitative Ct ◽  
Load Response ◽  
Force Calculation

Background and objectives: There are no reports on articular stress distribution during walking based on any computed tomography (CT)-finite element model (CT-FEM). This study aimed to develop a calculation model of the load response (LR) phase, the most burdensome phase on the knee, during walking using the finite element method of quantitative CT images. Materials and Methods: The right knee of a 43-year-old man who had no history of osteoarthritis or surgeries of the knee was examined. An image of the knee was obtained using CT and the extension position image was converted to the flexion angle image in the LR phase. The bone was composed of heterogeneous materials. The ligaments were made of truss elements; therefore, they do not generate strain during expansion or contraction and do not affect the reaction force or pressure. The construction of the knee joint included material properties of the ligament, cartilage, and meniscus. The extensor and flexor muscles were calculated and set as the muscle exercise tension around the knee joint. Ground reaction force was vertically applied to suppress the rotation of the knee, and the thigh was restrained. Results: An FEM was constructed using a motion analyzer, floor reaction force meter, and muscle tractive force calculation. In a normal knee, the equivalent stress and joint contact reaction force in the LR phase were distributed over a wide area on the inner upper surface of the femur and tibia. Conclusions: We developed a calculation model in the LR phase of the knee joint during walking using a CT-FEM. Methods to evaluate the heteromorphic risk, mechanisms of transformation, prevention of knee osteoarthritis, and treatment may be developed using this model.

The Effects of Modelling Techniques and Data Uncertainty in Wellhead Fatigue Life Calculation

2012 ◽  
Author(s):  
Dara Williams ◽  
John Greene
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Fatigue Damage ◽  
Environmental Data ◽  
Nonlinear Load ◽  
Soil Response ◽  
Load Response ◽  
Highly Nonlinear ◽  
Non Linear ◽  
The Impact

Offshore oil and gas exploration continues to move into deeper and more harsh environments and consequently the response of drilling riser systems and associated fatigue loading transmitted to the wellhead and conductor system are of key importance in the design of offshore wells. In addition the presence of ageing infrastructure in mature areas combined with requirements for future workover operations requires careful consideration of both past and future fatigue damage accumulation. In order to estimate remaining fatigue life for the wellhead and conductor the accumulation of damage from each stage of a drilling campaign and phase of operation of a well, including workover and completion operations, must be considered. Thus a detailed global finite element analysis of the impact of riser response, under wave and vortex induced vibration (VIV), on the conductor and wellhead structure is of critical importance. Traditional engineering evaluation methods to estimate fatigue of wellhead systems in offshore regions with limited availability of environmental data may result in an over estimation of fatigue damage accumulated in the wellhead. Any assumptions regarding fatigue current profiles can also lead to over-prediction of fatigue damage in the wellhead. This can have implications for the planning of future workover operations and may also lead to unnecessary over-design of the system. A further limitation of traditional wellhead fatigue evaluation criteria lies in the assumptions regarding riser tensioner system load response. These methods do not account for the highly nonlinear load response of the tensioner system and can thus significantly underestimate fatigue damage contribution. This paper presents a more detailed wellhead fatigue analysis methodology to incorporate new analysis techniques, as used for a number of recent applications, to assess with a greater level of refinement the impact of the riser motions on the wellhead fatigue. Specifically this methodology incorporates the generation of a detailed global finite element model of the riser and wellhead system to include detailed non-linear riser tensioner system models, accurate models of the wellhead and conductor, detailed non-linear soil response characteristics and the use of more refined current data as input to VIV calculations. The details of the riser and wellhead system model are presented and the conservatisms associated with traditional modeling methods with regard to VIV and riser tensioner load variations are discussed. A number of case studies are presented to illustrate the effects of various data assumptions and simplifications on estimated wellhead fatigue.

Design guidelines and optimization of ultra-high-performance fibre-reinforced concrete blast protection wall panels

2020 ◽  
Vol 11 (4) ◽  
pp. 494-514
Author(s):  
Mohtady Sherif ◽  
Hesham Othman ◽  
Hesham Marzouk ◽  
Hassan Aoude
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
High Performance ◽  
Optimization Techniques ◽  
Blast Load ◽  
Fibre Reinforced Concrete ◽  
Blast Loads ◽  
Finite Element Software ◽  
Wall Panels ◽  
High Performance Fibre

Ultra-high-performance fibre-reinforced concrete is the latest generation of structural concrete, having outstanding fresh and hardened properties; this includes the ease of placement and consolidation with ultra-high mechanical properties, as well as toughness, volume stability, durability, higher flexural and tensile strength, and ductility. As more research is being focused on it, the material behaviour and characteristics are getting more understood, and the research demand for the special applications of the ultra-high-performance fibre-reinforced concrete is growing higher. One special application that ultra-high-performance fibre-reinforced concrete is thought to have an outstanding performance at is in the field of protective structures, specifically against blast loads. This article presents part of a study that is concerned with the behaviour and response of ultra-high-performance fibre-reinforced concrete wall panels under blast load. Size and shape optimization techniques were combined in this study to optimize the design of a 200-MPa ultra-high-performance fibre-reinforced concrete under blast loads using finite element modelling. This design optimization aims to maximize stiffness and minimize the cost while satisfying both design stresses and construction requirements. The design variable to be optimized for are the thickness ranging from 100 to 300 mm at 25 mm increments, in addition to the reinforcement ratio of 0%, 0.2%, 1% and 3%, and aspect ratio of 1, 1.5 and 2; the boundary condition is four edges fixed and restrained. The numerical simulation has been performed using an explicate finite element software package. The complete behaviour of an ultra-high-performance fibre-reinforced concrete is defined using the concrete damaged plasticity model. The concrete constitutive model has been developed considering the contribution of tensile hardening response, fracture energy and crack-band width approaches to accurately represent the tensile behaviour and guarantee mesh independence of results. The blast load is applied using the Conventional Weapons method of the US Army Corps of Engineers that is readily available in the finite element software. The validity of the numerical model used is verified by comparing numerical results to experimental data.

scholarly journals SELECTING THE BEST ARCHITECTURAL FORM OF THE OFFICE BUILDING WITH THE LEVEL OF NON-STOP FUNCTION AGAINST EXPLOSION

2015 ◽  
Vol 7 (2) ◽  
pp. 81-90
Author(s):  
Jalal Nakhaei ◽  
Mahdi Bitrafan ◽  
Shahin Lale Arefi ◽  
Hossein Samee
Keyword(s):  
Finite Element Method ◽  
Sustainable Development ◽  
Finite Element ◽  
Blast Wave ◽  
Blast Loading ◽  
Building Construction ◽  
Office Building ◽  
Blast Load ◽  
Architectural Form

Regarding the importance of structures in sustainable development of countries, the necessity to consider them versus inflicted forces has an especial position. One of the inflicted forces upon these structures is explosion. Given that the resistance of a construction against blast wave depends on the form and shape of the building, numbers of trap doors and openings, power and quality of materials utilized in the building; in consequence, studying and evaluating types of construction forms versus outcomes resulted from explosion find importance. The behavior of three kinds of buildings including the forms of cone, hemisphere and frustum were, therefore, evaluated in the research. Various methods can be applied in order to assess behavior of construction against blast load, however, Finite Element method has been utilized in the article duo to particular capabilities of it in the blast assessments. Then, results of blast loading over the constructions were surveyed and it was concluded that buildings with hemispherical form show the best manner and providing openings called colloquially blast walls are used in the building; construction resistance versus blast load is raised.

Sign in / Sign up

Export Citation Format

Share Document