Numerical Simulation and Analysis of the Aircraft Pilot Seat Impact Resistance

Author(s):  
Xiaoyu Zhang ◽  
Xiang Jinwu ◽  
Mengxiao Li ◽  
Yiru Ren
Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3283
Author(s):  
Guoqiang Luo ◽  
Yuxuan Zhu ◽  
Ruizhi Zhang ◽  
Peng Cao ◽  
Qiwen Liu ◽  
...  

Cellular media materials are used for automobiles, aircrafts, energy-efficient buildings, transportation, and other fields due to their light weight, designability, and good impact resistance. To devise a buffer structure reasonably and avoid resource and economic loss, it is necessary to completely comprehend the constitutive relationship of the buffer structure. This paper introduces the progress on research of the mechanical properties characterization, constitutive equations, and numerical simulation of porous structures. Currently, various methods can be used to construct cellular media mechanical models including simplified phenomenological constitutive models, homogenization algorithm models, single cell models, and multi-cell models. This paper reviews current key mechanical models for cellular media, attempting to track their evolution from their inception to their latest development. These models are categorized in terms of their mechanical modeling methods. This paper focuses on the importance of constitutive relationships and microstructure models in studying mechanical properties and optimizing structural design. The key issues concerning this topic and future directions for research are also discussed.


Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 890
Author(s):  
Huiling Zhao ◽  
Xiangqing Kong ◽  
Ying Fu ◽  
Yihan Gu ◽  
Xuezhi Wang

To precisely evaluate the retrofitting effectiveness of Carbon Fiber Reinforced Plastic (CFRP) sheets on the impact response of reinforced concrete (RC) T-beams, a non-linear finite element model was developed to simulate the structural response of T-beams with CFRP under impact loads. The numerical model was firstly verified by comparing the numerical simulation results with the experimental data, i.e., impact force, reaction force, and mid-span displacement. The strengthening effect of CFRP was analyzed from the section damage evaluation. Then the impact force, mid-span displacement, and failure mode of CFRP-strengthened RC T-beams were studied in comparison with those of un-strengthened T-beams. In addition, the influence of the impact resistance of T-beams strengthened with FRP was investigated in terms of CFRP strengthening mode, CFRP strengthening sizes, CFRP layers and FRP material types. The numerical simulation results indicate that the overall stiffness of the T-beams was improved significantly due to external CFRP strips. Compared with the un-strengthened beam, the maximum mid-span displacement of the CFRP-strengthened beam was reduced by 7.9%. Additionally, the sectional damage factors of the whole span of the CFRP-strengthened beam were reduced to less than 0.3, indicating that the impact resistance of the T-beams was effectively enhanced.


2019 ◽  
Vol 11 (5) ◽  
pp. 723-736
Author(s):  
Radek Doubrava ◽  
Martin Oberthor ◽  
Petr Bělský ◽  
Jan Raška

Purpose The purpose of this paper is to describe the approach for the design of a jet engine composite air inlet for a new generation of jet trainer aircraft from the perspective of airworthiness requirements regarding high-speed impact resistance. Design/methodology/approach Validated numerical simulation was applied to flat test panels. The final design was optimised and verified by validated numerical simulation and verified by testing on a full-scale demonstrator. High-speed camera measurement and non-destructive testing (NDT) results were used for the verification of the numerical models. Findings The test results of flat test panels confirmed the high durability of the composite structure during inclined high-speed impact with a near-real jet inlet load boundary condition. Research limitations/implications Owing to the sensitivity of the composite material on technology production, the results are limited by the material used and the production technology. Practical implications The application of flat test panels for the verification and tuning of numerical models allows optimised final design of the air inlet and reduces the risk of structural non-compliance during verification tests. Originality/value Numerical models were verified for simulation of the real composite structure based on high-speed camera results and NDT inspection after impact. The proposed numerical model was simplified for application in a real complex design and reduced calculation time.


2015 ◽  
Vol 1095 ◽  
pp. 698-703
Author(s):  
Ning Ma ◽  
Ke Su Liu ◽  
Quan Kun Liu ◽  
Yu Jie Ma

The hot stamping process and process parameters are investigated for a model of a B-pillar outer plate by numerical simulation. The feasibility of hot stamping forming process and its parameters are analyzed. The effectiveness of numerical simulation and the accuracy of hot stamping forming process and its parameters for B-pillar outer plate are proved by the hot stamping experiment and tensile tests. Three models are designed to analyze the effect of B-pillar in the vehicle side impact. It shows that hot stamping technology has the advantages in the field of lightweight and improving impact resistance. Through the research of the historical process of hot forming part, the residual strain characteristics of hot stamping parts is analyzed, the produce and mechanism of residual strain is explained, and the application method based on the forming history of hot stamping technology is provided.


2018 ◽  
Vol 188 ◽  
pp. 04006
Author(s):  
Radek Doubrava ◽  
Martin Oberthor ◽  
Petr Bělský ◽  
Jan Raška

Bird or hail stone impacts are an important phenomenon that must be taken into consideration when designing aircraft. As engines are the sole thrust-providing mechanisms of an aircraft, it is critical that the effects of bird or hail stone strikes on engine inlets and systems be investigated and mitigated to the greatest extent possible. A combination of experiments and numerical simulations is necessary to properly understand the behaviour of a bird or hail stone during impact and the reaction of the impacted material with the structure. A simulation methodology is developed and validated to certify the bird or hail stone strike resistance of composite air ducts designed for a new generation of jet training aircraft. Physical impact tests were performed on real composite parts. Numerical simulation results were compared with test results. Numerical simulation was also used for test preparation and optimization of the test rig design from the point of view of the influence of the stiffness of the surrounding aircraft structure. The validated modelling procedure allows the analysis of numerous impact scenarios, improving the optimization procedures for aircraft component design and reducing the cost of development by reducing the need to manufacture test prototypes.


Author(s):  
Shuai Yang ◽  
Xiao-zhou Xia ◽  
Qing Zhang ◽  
Xue-gang Wang ◽  
Zong-quan Ying

Abstract The consecutive multiple impact resistance of reinforced concrete pier column becomes the most concern in the engineering field. Numerical simulation the process of consecutive multiple lateral impacts is the necessary measures to master the internal mechanism. The fine 3D finite element model is established combining solid element and beam element. The dynamic damage constitutive model of concrete is developed. To react to problem of calculative efficiency and damage accumulation effect, the reduced integration method and full restart analytical method of explicit dynamic analysis strategy is taken using element failure criterion. The translation process of the system energy, the time history value of impact mass acceleration and strain gauge and failure mode of the reinforced concrete pier are compared with the experiment results. The feasibility of the modelling and the validity of the analysis strategy are validated. This study can provide computation basis for research of reinforced concrete structures under consecutive multiple impact.


2021 ◽  
Vol 1166 ◽  
pp. 57-64
Author(s):  
Tomohisa Kojima ◽  
Masahiro Suzuki ◽  
Mitsuo Notomi

The impact resistance improvement is important for window glass to protect people from injury. Although it has been proved that the impact resistance of a glass plate can be improved easily by fitting a thin polymeric film, its mechanism has not been clarified yet. The purpose of this study is to clarify the reinforcing mechanism of the impact resistance of a glass plate by fitting a polymeric film. To clarify it, a numerical simulation model was built using ANSYS Autodyn to simulate the dynamic fracture of a glass plate fitted with a polymeric film. The simulation model and results were examined by comparing them to the experimental result in the previous study. The Johnson-Holmquist (JH2) damage model was used for the constitutive law of the glass plate. A polymeric film with 0.2 mm thickness (3% with the glass plate) was modeled at the non-impact surface of the glass plate. The nodes of the glass plate at the interface with the film connected the nodes of the film by perfect bonding. By comparing the simulation results to the experiment, it was indicated the importance of modeling the remaining fragments of the glass plate and the adhesive layer of the film in simulating the dynamic fracture of the glass plate fitted with polymeric film.


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