High Speed Bird Impact Testing of Aircraft Transparencies.

1978 ◽  
Author(s):  
M. J. Coker ◽  
R. H. Magnusson
Keyword(s):  
High Speed ◽  
Impact Testing ◽  
Bird Impact

Experimental and FEM study of windshield subjected to high speed bird impact

2003 ◽  
Vol 19 (6) ◽  
pp. 543-550 ◽  
Author(s):  
Yang Jialing ◽  
Cai Xujie ◽  
Wu Cunhao
Keyword(s):  
High Speed ◽  
Bird Impact

Correlating Drop Impact Simulations With Drop Impact Testing Using High-Speed Camera Measurements

2009 ◽  
Vol 131 (1) ◽  
Author(s):  
J. J. M. Zaal ◽  
W. D. van Driel ◽  
F. J. H. G. Kessels ◽  
G. Q. Zhang
Keyword(s):  
High Speed ◽  
Simulation Models ◽  
3D Models ◽  
Drop Impact ◽  
Impact Testing ◽  
Navigation Systems ◽  
High Speed Camera ◽  
Impact Performance ◽  
Impact Simulations ◽  
Board Level

The increased use of mobile appliances such as mobile phones and navigation systems in today’s society has resulted in an increase in reliability issues related to drop performance. Mobile appliances are dropped several times during their lifespan and the product is required to survive common drop accidents. A widely accepted method to assess the drop reliability of microelectronics on board-level is the drop impact test. This test has been standardized by international councils such as Joint Electron Device Engineering Council and is widely adopted throughout the industry. In this research the solder loading is investigated by combining high-speed camera measurements of several drop impact tests with verified finite element models. These simulation models are developed in order to gain an insight on the loading pattern of solder joints based on interconnect layout, drop conditions, and product specifications prior to physical prototyping. Deflections and frequencies during drop testing are measured using a high-speed camera setup. The high-speed camera experiments are performed on two levels: machine level (rebounds with and without a catcher) and product level (with different levels of energy and different pulse times). Parametric (dynamic and quasistatic) 3D models are developed to predict the drop impact performance. The experimental results are used to verify and enhance the simulation models, e.g., by tuning the damping parameters. As a result, the verified models can be used to determine the location of the critical solder joint and to obtain estimates of the solder lifetime performance.

Dynamic Analysis of Thin Glass Under Ball Drop Impact With New Metrics

2013 ◽  
Author(s):  
Liang Xue ◽  
Claire R. Coble ◽  
Hohyung Lee ◽  
Da Yu ◽  
Satish Chaparala ◽  
...  
Keyword(s):  
High Speed ◽  
Impact Testing ◽  
Image Correlation ◽  
Thin Glass ◽  
Fea Model ◽  
Wear And Tear ◽  
Local Measurements ◽  
Drop Impacts ◽  
Global And Local ◽  
The Impact

Response of brittle plate to impact loads has been the subject of many research studies [1–7]. Specifically, glass presents a wide variety of applications in daily life, and helps to protect the displays of smartphones, tablets, PCs, and TVs from everyday wear and tear. Therefore, the necessity of glass to resist scratches, drop impacts, and bumps from everyday use leads to the importance of investigation of the glass response under dynamic impact loading. The ball drop test has been applied in the past, specifying an energy threshold as a prediction metric. Use of energy as the key parameter in impact testing is limited, since it does not account for the time spent in contact during the impact event. This study attempts to establish a reliable metric for impact testing based on a momentum change threshold. The deformation and the strain of the glass will be obtained by the Digital Image Correlation (DIC) system, while the rebound velocity will be measured with the high speed cameras. The global and local measurements are conducted to verify the accuracy of the experimental results. Finally, the FEA model is developed using ANSYS/LS-DYNA to provide a comprehensive understanding of the dynamic response of the glass. Excellent correlation in deflection is obtained between the measurements and predictions.

Development and Evaluation of Silicon Nitride Components for Ceramic Gas Turbine

1998 ◽  
Author(s):  
Yasushi Hara ◽  
Katsura Matsubara ◽  
Ken-ichi Mizuno ◽  
Toru Shimamori ◽  
Hiro Yoshida
Keyword(s):  
Silicon Nitride ◽  
Gas Turbines ◽  
High Speed ◽  
Gas Flow ◽  
Impact Damage ◽  
Turbine Blades ◽  
Impact Testing ◽  
Particle Impact ◽  
Inlet Temperature ◽  
Power Turbine

NGK Spark Plug Co., Ltd. has been developing various silicon nitride materials, and the technology for fabricating components for ceramic gas turbines (CGT) using theses materials. We are supplying silicon nitride material components for the project to develop 300 kW class CGT for co-generation in Japan. EC-152 was developed for components that require high strength at high temperature, such as turbine blades and turbine nozzles. In order to adapt the increasing of the turbine inlet temperature (TIT) up to 1350 °C in accordance with the project goals, we developed two silicon nitride materials with further improved properties: ST-1 and ST-2. ST-1 has a higher strength than EC-152 and is suitable for first stage turbine blades and power turbine blades. ST-2 has higher oxidation resistance than EC-152 and is suitable for power turbine nozzles. On applying these silicon nitride ceramics to CGT engine, we evaluated various properties of silicon nitride materials considering the environment in CGT engine. Particle impact testing is one of those evaluations. Materials used in CGT engine are exposed in high speed gas flow, and impact damage of these materials is considered to be a concern. We tested ST-1 in the particle impact test. In this test, we observed fracture modes, and estimated the critical impact velocity. This paper summarizes the development of silicon nitride components, and the result of evaluations of these silicon nitride materials.

High and Low Speed Impact Characteristics of Nanocomposites

2015 ◽  
Vol 1105 ◽  
pp. 62-66 ◽  
Author(s):  
Saud Aldajah ◽  
Yousef Haik ◽  
Kamal Moustafa ◽  
Ammar Alomari
Keyword(s):  
High Speed ◽  
Impact Resistance ◽  
Absorption Capacity ◽  
Impact Testing ◽  
Energy Absorption Capacity ◽  
Low Speed ◽  
High Speed Impact ◽  
Bulletproof Vest ◽  
Impact Characteristics ◽  
The Impact

Nanocomposites attracted the attention of scientists due to their superior mechanical, thermal, chemical and electrical properties. This research studied the impact of adding carbon nanotubes (CNTs) to the woven Kevlar laminated composites on the high and low speed impact characteristics. Different percentages of CNTs were added to the woven Kevlar-Vinylester composite materials. An in-house developed drop weight testing apparatus was utilized for the low speed impact testing. Two different concentrations of the CNTs were added to a 15-layer woven Kevlar laminates, 0.32 wt% and 0.8 wt%. The results showed that: The 0.32 wt % CNT sample enhanced the interlaminar strength of the composite without enhancing the energy absorption capacity whereas, the 0.8 wt % CNT sample did not improve the impact resistance of the Kevlar composite.For the high speed impact tests, a bulletproof vest was prepared using woven Kevlar, resin, and CNTs at 1.5 w% percentage. The ballistic shooting was carried out by a professional shooter using a 30 caliber and 9 mm bullets for the tests. The CNT bulletproof sample bounced back the 30 caliber copper alloy bullet with no penetration.

scholarly journals Verification and application of bird strike analysis for the design of high-speed helicopter composite cowlings

2021 ◽  
Vol 349 ◽  
pp. 04011
Author(s):  
Radek Doubrava ◽  
Martin Oberthor ◽  
Petr Bělský ◽  
Bohuslav Cabrnoch
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Direct Method ◽  
Bird Strike ◽  
Aircraft Structures ◽  
Important Phenomenon ◽  
Impact Experiment ◽  
Bird Impact ◽  
Impact Experiments ◽  
A Direct Method

Bird strikes are an important phenomenon that must be taken into consideration when designing aircraft. A bird impact experiment provides a direct method to examine the bird strike resistance. However, the design of the aircraft structures usually involves many iterations of design-manufacturing-test and conducting bird impact experiments is not only time consuming but also costly. The aim of this work is to show the application of test verified numerical simulation for the design of composite cowlings of the high-speed helicopter.

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