Effect of Grain Size on the Performance of Extruded Magnesium Alloy Tubes in Three-Point Bending

2009 ◽  
Vol 618-619 ◽  
pp. 523-526
Author(s):  
Tim B. Hilditch ◽  
Dale Atwell ◽  
Aiden G. Beer
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Energy Absorption ◽  
Carrying Capacity ◽  
Peak Load ◽  
Load Carrying Capacity ◽  
Three Point Bending ◽  
Load Carrying

The performance of extruded AZ31, AZ61 and AM-EX1 tubes was examined in three-point bending. Different extrusion temperatures were used to investigate the effect of grain size on the load-carrying capacity, energy absorption and fracture propensity of the tubes. Results showed that while the peak load increased with a smaller average recrystallised grain size, the retention of large elongated un-recrystallised grains in the microstructure reduced the load. The presence of the large elongated grains also appeared detrimental to the ability of the tube to deform before fracture.

Bending Collapse Behaviour of Polyurethane Foam-Filled Rectangular Magnesium Alloy AZ31B Tubes

2015 ◽  
Vol 828-829 ◽  
pp. 259-264 ◽  
Author(s):  
Ping Zhou ◽  
Elmar Beeh ◽  
Horst E. Friedrich ◽  
Michael Kriescher ◽  
Philipp Straßburger ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Energy Absorption ◽  
Specific Energy ◽  
Carrying Capacity ◽  
Material Model ◽  
Load Carrying Capacity ◽  
Specific Energy Absorption ◽  
Magnesium Alloy Az31b ◽  
Load Carrying ◽  
Foam Filled

Quasi-static/dynamic three-point bending tests were conducted to assess the crash performance of magnesium alloy AZ31B extruded and sheet tubes at the German Aerospace Centre (DLR) – Institute of Vehicle Concepts in Stuttgart. Different foam-filled AZ31B beams with a variation of foam density and thickness were fabricated through several manufacturing processes: cold bending, tungsten inert gas welding, cathodic dip painting and polyurethane foam injection. The experimental results were compared with those from mild steel DC04 tubes. It shows that empty magnesium alloy AZ31B outperforms steel DC04 in terms of specific energy absorption for the empty tubes with equivalent volume when subjected to bending loads. It was found that the foam-filled tubes achieved much higher load carrying capacity and specific energy absorption than the empty tubes. Moreover, there is a tendency showing that a foam-filled beam with a higher foam density reaches higher load carrying capacity, but fractures earlier. The foam-filled AZ31B tube with 0.20 g/cm3foam obtained the highest specific energy absorption, but this outperformance was weakened due to the earlier fracture. In addition, the numerical simulation utilising material model MAT_124 in LS-DYNA explicit FEA package was performed. The simulation results indicate that using calibrated stress-strain curves and failure parameters, material model MAT_124 yields a general good agreement with the experimental results.

scholarly journals Performance of Sprayed Fiber Reinforced Polymer Strengthened Timber Beams

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
S. Talukdar ◽  
N. Banthia
Keyword(s):  
Energy Absorption ◽  
Carrying Capacity ◽  
Absorption Capacity ◽  
Fiber Reinforced Polymer ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Bonding Agents ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Timber Beams

A study was carried out to investigate the use of Sprayed Fiber Reinforced Polymer (SFRP) for retrofit of timber beams. A total of 10-full scale specimens were tested. Two different timber preservatives and two different bonding agents were investigated. Strengthening was characterized using load deflection diagrams. Results indicate that it is possible to enhance load-carrying capacity and energy absorption characteristics using the technique of SFRP. Of the two types of preservatives investigated, the technique appears to be more effective for the case of creosote-treated specimens, where up to a 51% improvement in load-carrying capacity and a 460% increase in the energy absorption capacity were noted. Effectiveness of the bonding agent used was dependent on the type of preservative the specimen had been treated with.

Key Performance Indicators of Tubes Used as Energy Absorbers

2014 ◽  
Vol 626 ◽  
pp. 155-161 ◽  
Author(s):  
T.X. Yu ◽  
Yan Fei Xiang ◽  
Min Wang ◽  
Li Ming Yang
Keyword(s):  
Energy Absorption ◽  
Carrying Capacity ◽  
Performance Indicators ◽  
Key Performance Indicators ◽  
Absorption Capacity ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Engineering Designs ◽  
Energy Absorbers ◽  
Energy Absorbing

Based on our extensive studies on the experimental, theoretical and numerical results on various tubes under axial compression/impact in the last few years, we propose a set of Key Performance Indicators (KPIs) to assess and compare the energy absorbing performance of tubular structures with various configurations, so as to guide the design of energy absorbers whilst to archive a certain degree of optimization. The KPIs have five factors: Effective stroke ratio (ESR), Non-dimensional Load-carrying capacity (NLC), Effectiveness of energy absorption (EEA), Specific energy absorption capacity (SEA), Stableness of load-carrying capacity (SLC).The paper presents a series of diagrams to compare the energy absorbing performance of various tubes in terms of the four KPIs as described above. The work is valuable to engineering designs and applications, as well as to the further studies of the topic.

Key Performance Indicators of Tubes and Foam-Filled Tubes Used as Energy Absorbers

2015 ◽  
Vol 07 (04) ◽  
pp. 1550060 ◽  
Author(s):  
Yanfei Xiang ◽  
Min Wang ◽  
Tongxi Yu ◽  
Liming Yang
Keyword(s):  
Energy Absorption ◽  
Carrying Capacity ◽  
Performance Indicators ◽  
Key Performance Indicators ◽  
Load Carrying Capacity ◽  
Tubular Structures ◽  
Load Carrying ◽  
Foam Filled ◽  
Energy Absorbers ◽  
Energy Absorbing

Based on a systematic investigation on the experimental, theoretical and numerical results on various tubes under axial compression/impact including our own tests, a set of key performance indicators (KPIs) for assessing and comparing the energy absorbing performance of tubular structures with various configurations is proposed, so as to guide the design of energy absorbers whilst to facilitate parameter optimization. The five KPIs proposed on the basis of mechanical analyses are effective stroke ratio (ESR), nondimensional load-carrying capacity (NLC), specific energy absorption (SEA), effectiveness of energy absorption (EEA) and undulation of load-carrying capacity (ULC). Moreover, by considering the influence of foam filling, these five KPIs are also modified and extended to the foam-filled tubes. The paper presents a series of diagrams to compare the energy absorbing performance of various tubes in terms of the five KPIs as described above. It transpires that the energy absorption performance of circular tubes is superior to that of square tubes. It is also confirmed that the mass of foam fillers results in reductions of SEA and EEA, though foam fillers will greatly improve the NLC of empty tubes. The novelty of the present study is displayed on the following aspects: (1) uniquely defining the effective stroke by the maximum point of "energy efficiency" f so as to avoid ambiguity which appeared in the literature; (2) instead of a single indicator such as SEA, proposing a set of five KPIs to comprehensively assess the performance of energy absorbers and (3) validating the usefulness of the proposed KPIs by comparing the performance of various tubular structures used as energy absorbers.

scholarly journals Manufacturing and Performance Evaluation of Carbon Fiber–Reinforced Honeycombs

2019 ◽  
Vol 3 (1) ◽  
pp. 13 ◽  
Author(s):  
Sanjeev Rao ◽  
Jimmy Thomas ◽  
Alia Aziz ◽  
Wesley Cantwell
Keyword(s):  
Performance Evaluation ◽  
Carbon Fiber ◽  
Energy Absorption ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Static Compression ◽  
Epoxy Resin System ◽  
Load Carrying ◽  
Carbon Fiber Reinforced

In this work, the manufacturing characteristics and a performance evaluation of carbon fiber–reinforced epoxy honeycombs are reported. The vacuum-assisted resin transfer molding process, using a central injection point, is used to infuse a unidirectional dry slit tape with the epoxy resin system Prime 20 LV in a wax mold. The compression behavior of the manufactured honeycomb structure was evaluated by subjecting samples to quasi-static compression loading. Failure criteria for the reinforced honeycombs were developed and failure maps were constructed. These maps can be used to evaluate the reliability of the core for a prescribed loading condition. Improvements in the load-carrying capacity for the reinforced samples, as compared with unreinforced specimens, are discussed and the theoretical predictions are compared with the experimental data. The compression test results highlight a load-carrying capacity up to 26 kN (~143 MPa) for a single hexagonal cell (unit cell) and 160 kN (~170 MPa) for cores consisting of 2.5 × 3.5 cells. The failure map indicates buckling to be the predominant mode of failure at low relative densities, shifting to cell wall fracture at relative densities closer to a value of 10−1. The resulting energy absorption diagram shows a monotonic increase in energy absorption with the increasing t/l ratio of the honeycomb core cell walls.

scholarly journals Push-Out Tests on Various Steel Anchors with Partial-Length Welding in Steel–Concrete Composite Members

2020 ◽  
Vol 11 (1) ◽  
pp. 105
Author(s):  
In-Rak Choi ◽  
Chang-Soo Kim
Keyword(s):  
Carrying Capacity ◽  
Peak Load ◽  
Steel Beams ◽  
Load Reduction ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Partial Length ◽  
Load Carrying ◽  
Ductile Behavior ◽  
Push Out

To investigate the behavior of various steel anchors, push-out tests were performed for 13 test specimens. Test parameters included the geometry of beams (wide-flange beams and composite beams) and the type of steel anchors (stud anchors and Z- and C-channel anchors with full- or partial-length welding). Test results showed that the performance of test specimens strongly depends on the types of steel anchors rather than the geometry of steel beams. The specimens with C-channel anchors showed the highest load-carrying capacity but the most drastic load reduction after the peak load. The specimens with Z-channel anchors showed a similar behavior to those with C-channel anchors but the load reduction occurred at a slightly slower rate. The load-carrying capacity was increased with the length of the Z- and C-channel anchors. The specimens with stud anchors reached the peak load at a slow rate and showed the most ductile behavior. The test results were compared with predictions by various design equations for steel anchors available in the literature, and the existing design equations for channel anchors with partial-length welding were considered applicable to design.

scholarly journals Effect of Fibrous Jacket on Behavior of RC Columns

2020 ◽  
Vol 6 (10) ◽  
pp. 1876-1894
Author(s):  
Wathiq Jassim ◽  
Samir M. Chassib
Keyword(s):  
Energy Absorption ◽  
Carrying Capacity ◽  
Load Capacity ◽  
Ultimate Stress ◽  
Steel Fibers ◽  
Load Carrying Capacity ◽  
Cross Sectional ◽  
Absorption Increase ◽  
Short Columns ◽  
Load Carrying

This paper presented an extensive study about the strengthening of RC square short columns with high strength concrete jackets reinforced with steel fiber. The aim of this study is to investigate the effect of confinement by fibrous jacket on the behavior of RC column. A comparative study is performed on 23 square columns (six of them were unconfined columns where the remaining seventeen were confined columns) with varied parameters such as steel fibers ratio and type, jacket thickness, partial and full strengthening, type of confining jacket (hoop and composite), use of epoxy as bond material between the concrete column and strengthening jacket, and length parameter. The test results showed that the strengthened columns showed a significant improvement in the ultimate stress, load-carrying capacity, maximum strain, ductility, and energy absorption. Increase the steel fibers ratio (1, 1.5 and 2%) increased the ultimate stress by (22.5, 12.3 and 12.5%) respectively. The use of epoxy as bond material enhanced the ultimate stress by an average improvement by (55%). Composite case in the strengthening enhanced the load-carrying capacity larger than hoop case by (28.7 and 42%) for FRC jackets with hooked and straight fibers respectively but in case of stress capacity, hoop jacket carries stresses more than composite according to the stressed cross-sectional area. Increase jacket thickness (25 and 35 mm) enhanced the ultimate stress by (28.7 and 15.5%) respectively. Partial strengthening has a good enhancement in the ultimate load but was less than full strengthening. Increase the length by (25 cm) decreased the enhancement in load capacity of the column with hoop jacket by (45.3%). Concrete jackets enhanced Energy absorption and ductility which improved the deformation capacity. The compressive behavior of stub concrete columns was also modeled, simulated, and analyzed numerically by a 3D nonlinear finite element model. The verification process was performed against the reported data of the experimental test which proved the results of experimental results and showed a good agreement between experimental and numerical outcomes.

COLLAPSE TEST ON RECTANGULAR STEEL BEAM WITH DIFFERENT SUPPORT CONDITION

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Sung-Hyun Park ◽  
Kyung Jae Shin ◽  
Swoo-Heon Lee ◽  
Hee-Du Lee ◽  
Woo Bum Kim
Keyword(s):  
Carrying Capacity ◽  
Tensile Force ◽  
Peak Load ◽  
Load Carrying Capacity ◽  
Collapse Load ◽  
Support Condition ◽  
Catenary Action ◽  
Peak Loads ◽  
Load Carrying ◽  
Second Peak

The behavior of beams with different support condition was investigated through three-point bending test for the purpose of studying difference of maximum load and catenary action of a beam. Beams are made of SPSR400 which has 245MPa of nominal yield strength and 400MPa of nominal tensile strength. The parameters of the supports condition are simple support and rotationally semi-rigid connection with different horizontal reaction strength applied by anchors. The support boundary conditions of beams were classified into three types; (A) simply supported with no anchors, (B) embedded anchors with 50mm depth of φ10mm, and (C) embedded anchors with 80mm depth of φ10mm. Both ends of the beams were connected by fillet welded angles and supported on a rigid concrete wall through anchors. The test result shows how much the load carrying capacity is increased by catenary action after large deflection at the center of the beam. First peak loads from each types are the loads when first plastic hinge occurs at the mid-span. There were no significant differences among the first peak loads measured from three types. After that, tensile force at anchors due to catenary action increased the load carrying capacity by approximately 55%, which is called as the second peak load. However, second peak load happens when the anchors at a support fully resist a tensile force, therefore it doesn’t happen with type (A) and (B). In conclusion, support boundary conditions of a beam don’t have an effect on the first collapse load, but the second collapse load is increased as embedded length of an anchor becomes deeper.

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