scholarly journals Emergency Separation Simulation and Damage Prediction of an Airliner under Wheel-Up Landing Condition

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Pengfei Zhang ◽  
Hong Nie ◽  
Jianfei Wu ◽  
Muqi Yu
Keyword(s):  
Damage Model ◽  
Constitutive Models ◽  
Maximum Load ◽  
Metallic Materials ◽  
Test Results ◽  
Static Test ◽  
Damage Prediction ◽  
Drop Hammer ◽  
Separation Sequence ◽  
Bar Test

To predict the damage to and response of aircraft structures during wheel-up crash landing, numerical simulations were performed using a constitutive and damage model for ductile metallic materials developed in the ABAQUS/Explicit environment. The model of an entire aircraft and detailed submodels were established. The Johnson–Cook and Gurson material constitutive models were validated by conducting Hopkinson’s bar test. A drop hammer test and a static test of the fuse pins were performed to determine and verify the response and strength of the structure. The experimental and analytical results indicate that the stain rate and damage parameters significantly influence the emergency separation load, fuse pin strength, and separation sequence. The analysis results were compared with the test results, and a close agreement was found in terms of the maximum load and deformation.

Investigating the use of small-diameter softwood as guardrail posts: static test results

2007 ◽  
Author(s):  
David E. Kretschmann ◽  
Ron Faller ◽  
Jason Hascall ◽  
John Reid ◽  
Dean Sicking ◽  
...  
Keyword(s):  
Small Diameter ◽  
Test Results ◽  
Static Test

scholarly journals Null-Result Test for Effect on Weight from Large Electrostatic Charge

Physics ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 160-172
Author(s):  
G. Hathaway ◽  
L. L. Williams
Keyword(s):  
Scalar Field ◽  
Long Range ◽  
Buoyancy Force ◽  
Weak Field ◽  
Electrostatic Charge ◽  
Measurement Precision ◽  
Test Results ◽  
Static Test ◽  
Null Result ◽  
Test Objects

We report test results searching for an effect of electrostatic charge on weight. For conducting test objects of mass of order 1 kg, we found no effect on weight, for potentials ranging from 10 V to 200 kV, corresponding to charge states ranging from 10−9 to over 10−5 coulombs, and for both polarities, to within a measurement precision of 2 g. While such a result may not be unexpected, this is the first unipolar, high-voltage, meter-scale, static test for electro-gravitic effects reported in the literature. Our investigation was motivated by the search for possible coupling to a long-range scalar field that could surround the planet, yet go otherwise undetected. The large buoyancy force predicted within the classical Kaluza theory involving a long-range scalar field is falsified by our results, and this appears to be the first such experimental test of the classical Kaluza theory in the weak field regime, where it was otherwise thought identical with known physics. A parameterization is suggested to organize the variety of electro-gravitic experiment designs.

Experimental Investigation for Horizontal Ultimate Bearing Capacity and Target Ductility Factor Improvement Results of the RC Column Reinforced by AFL with Damages

2014 ◽  
Vol 488-489 ◽  
pp. 497-500
Author(s):  
You Lin Zou ◽  
Pei Yan Huang
Keyword(s):  
Bearing Capacity ◽  
Ultimate Bearing Capacity ◽  
Test Results ◽  
Rc Columns ◽  
Static Test ◽  
Rc Column ◽  
Ductility Factor ◽  
Secant Stiffness ◽  
Function Relationship ◽  
Reversed Cyclic

Deem test results from the low reversed cyclic loading quasi-static test with 2 RC columns as the basic information of secant stiffness damage of the reference column and take use of the TMS instrument in the test to artificially make the damage percentage of secant stiffness of the RC column as 33%, 50% and 66%, 6 damaged columns in total; reinforce the 6 damaged columns and 2 undamaged ones under the same conditions with AFL, through quasi-static contrast test. Test results show that it is able to effectively boost horizontal ultimate bearing capacity and ductility deformability of the RC columns with AFL for reinforcement; besides, there is a linear function relationship between horizontal ultimate bearing capacity, target ductility factor, and damage percentage of secant stiffness.

Design of Static Test Model for Three-Tower Cable-Stayed Self-Anchored Suspension Composed Bridge

2011 ◽  
Vol 243-249 ◽  
pp. 1528-1535
Author(s):  
Yu Zhao ◽  
Yong Jun Zhou ◽  
Jing Sun ◽  
Jin Tao Tang ◽  
Xu Li
Keyword(s):  
Complex System ◽  
Finite Element ◽  
Element Model ◽  
Test Model ◽  
Test Results ◽  
Static Test ◽  
Whole Process ◽  
Aesthetic Appearance ◽  
Load Carrying ◽  
Novel Structures

Cable-stayed self-anchored suspension composed bridges have novel structures and aesthetic appearance with complex system and difficulty for design and construction. In order to acquire a better knowledge of the load-carrying capability of this type of bridges, based on a real bridge and the theory of abnormal similarity, a full-bridge scaled down(1:20) test model was built to simulate the whole process of construction. The test results were preferably fit the theoretical calculation value. It can be seen that the design of the bridge was reasonable, and the accuracy of the calculation of finite element model was verified at the same time. The test and the related results can be used as the reference for the test and design of the similar bridges.

INFLUENCE OF THE DYNAMICS OF FORCED MOTION ON THE STATIC FRICTION IN METAL-POLYMER SLIDING PAIRS

Tribologia ◽  
2021 ◽  
Vol 295 (1) ◽  
pp. 21-26
Author(s):  
Mariusz Opałka ◽  
Wojciech Wieleba ◽  
Angelika Radzińska
Keyword(s):  
Relative Motion ◽  
Friction Pair ◽  
Polymeric Materials ◽  
Static Friction ◽  
Metallic Materials ◽  
Test Results ◽  
Friction Resistance ◽  
Rate Of Increase ◽  
Polymer Metal ◽  
Metal Polymer

The resistance during the frictional interaction of polymeric materials with metallic materials is characterized by a significant dependence on the dynamics of the motion inputs. In a metal-polymer friction pair, the static friction resistance during standstill under load depends on the rate of growth of the force causing the relative motion. Tribological tests of selected (polymer-metal) sliding pairs were carried out. The selected polymers were polyurethane (TPU), polysulfone (PSU), and silicone rubber (SI). They interacted with a pin made of normalized C45 steel under unitary pressure p = 0.5 MPa in dry friction conditions at different gradients of the force driving the relative motion (dF/dt = 0.1-20 [N/s]). The static friction coefficient of the selected sliding pairs was determined on the basis of the recorded static friction force values. The test results show a significant influence of the rate of increase in the motion driving force on the values of static friction resistance. This is mainly due to the viscoelastic properties of polymers.

scholarly journals Influence of stirrup spacing on shear resistance and deformation of reinforced concrete beams

2018 ◽  
Vol 7 (1) ◽  
pp. 126
Author(s):  
Latha M S ◽  
Revanasiddappa M ◽  
Naveen Kumar B M
Keyword(s):  
Concrete Beam ◽  
Concrete Beams ◽  
Bending Moment ◽  
Maximum Load ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Cement Concrete ◽  
Simply Supported ◽  
Reinforced Cement ◽  
Flexural Reinforcement

An experimental investigation was carried out to study shear carrying capacity and ultimate flexural moment of reinforced cement concrete beam. Two series of simply supported beams were prepared by varying diameter and spacing of shear and flexural reinforcement. Beams of cross section 230 mm X 300 mm and length of 2000 mm. During testing, maximum load, first crack load, deflection of beams were recorded. Test results indicated that decreasing shear spacing and decreasing its diameter resulted in decrease in deflection of beam and increase in bending moment and shear force of beam.

Nonlinear Numerical Optimization Design Applied to Wall-Thickness of Welding T Shaped Connecting HDPE Tube

2010 ◽  
Vol 97-101 ◽  
pp. 2991-2994
Author(s):  
Yong Chang Guo ◽  
Jun Deng ◽  
Hao Bin Xie
Keyword(s):  
Wall Thickness ◽  
Material Properties ◽  
Numerical Optimization ◽  
Optimization Design ◽  
Constitutive Models ◽  
Test Results ◽  
Swarm Optimization ◽  
Stress Contour ◽  
Distribution Of Stress ◽  
Pipeline Design

There are two reasons to enlarge the thickness of welding HDPE tri-branch tube. Firstly, welding weakens the HDPE material properties. Secondly, stress concentration occurs at the joint of tri-branch tube. The material properties of HDPE and the tensile strength of welding HDPE were tested. Based on the test results, the wall-thickness of HDPE tri-branch tube was investigated by numerical optimization design with particle swarm optimization (PSO). Two material constitutive models of elasto-palstic and Ramberg-Osgood for HDPE are adopted in FEM. Some valuable conclusions of pipeline design are concluded by the distribution of stress contour curves and optimization curves of welding joint of HDPE tri-branch tube.

Determination of Flow Curve Using Bulge Test and Calibration of Damage for Ito-Goya Models

2013 ◽  
Vol 554-557 ◽  
pp. 182-189 ◽  
Author(s):  
Bruno Martins ◽  
Abel D. Santos ◽  
Pedro Teixeira ◽  
K. Ito ◽  
N. Mori
Keyword(s):  
Tensile Test ◽  
Damage Model ◽  
Strain Curve ◽  
Uniaxial Tensile ◽  
Bulge Test ◽  
Uniaxial Tensile Test ◽  
Damage Prediction ◽  
Damage Models ◽  
Material Information

The standard uniaxial tensile test is the widely accepted method to obtain relevant properties of mechanical characterization of sheet metal materials. However the range of strain obtained from tensile test is limited. The bulge test is an alternative to obtain ranges of deformation, higher than tensile test, thus permitting a better characterization for material behaviour. This paper presents a sensitivity analysis for some influencing variables used in bulge measurements, thus giving some guidelines for the evaluation of the stress-strain curve from experimental results using a developed experimental mechanical system. Additionally, using bulge test up to fracture shall give material information regarding damage, which in turn may be used to evaluate and calibrate damage models. A methodology is presented to be used for evaluation and calibration of Ito-Goya damage model of damage prediction.

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