Analysis of Crushing Laminated Composite Square Tubes under Quasi-Static Loading

2013 ◽  
Vol 446-447 ◽  
pp. 113-116
Author(s):  
A. Othman ◽  
A.A. Arifin ◽  
S. Abdullah ◽  
A.K. Ariffin ◽  
N.A.N. Mohamed

This paper present on discusses the effect of crashworthiness parameters on pultrusion and hybrid laminated composite square tubes via experimentally. The wall-thicknesses of 2.1 for pultrusion and 1.6 mm aluminum wrap 1 layered were examined at the material fiber type of E-glass reinforced polyester resin of square cross-section subjected to axial quasi-static loading. Comparison has been made for both of type of composite material. During experimental observation, some of crushing modes on stages were identified as initial peak load stage, progressive crushing stage and compaction zone stage. The effects of crushing parameters and failure modes were analyzed and discussed. Results showed that the tubes energy absorption capability was affected significantly by varying of different type of composite in terms of composite fabrication and variable aspect of cross-section. It is also found that different type of fabrication on different manufacturing process of composite reveal in terms of internal energy during crushed events.

2013 ◽  
Vol 594-595 ◽  
pp. 711-714
Author(s):  
A.A. Arifin ◽  
A. Othman

The present paper determines the effect of crush force efficiency on laminate glass wrapped on aluminum cross-section square tubes under quasi-static loading. The analysis was examined via experimentally. The wall-thicknesses aluminum square of 1.6 mm was investigated on wrapped woven composite type of E-glass fiber reinforced polyester resin. Two different numbers of layers woven E-glass were investigated and examined. Result obtained from experimental analysis such that initial peak load, mean load, versus displacement curves were compared for each specimen. Results showed that the tubes energy absorption was affected significantly by different number of layers wrapped on wall aluminum square profile and also that the effect of crushing behaviors and failure modes was discussed.


2013 ◽  
Vol 594-595 ◽  
pp. 707-710
Author(s):  
A.A. Arifin ◽  
A. Othman

In this paper presents the effect of energy absorption on thin-walled aluminum cross-section square tubes wrapped with woven E-glass fiber laminated composite subjected to quasi-static axial compression. The compression test was carried out experimentally to examine the amount of energy can be absorbed as well as to observe for failure behavior for each specimens. The wall-thicknesses aluminum square of 1.9 mm was investigated and woven E-glass fiber laminate reinforced polyester resin was examined. Two different numbers of layers woven E-glass were investigated and examined. Result obtained from experimental analysis such that initial peak load, mean load, quasi-static absorbed energy against displacement curves were recoded and plotted then compared for each specimen profile. Results indicated that the tubes crashworthy structure was affected significantly by different number of layers wrapped on wall aluminum square profile and also that the effect of crushing behaviors and failure modes was discussed.


2013 ◽  
Vol 664 ◽  
pp. 649-653 ◽  
Author(s):  
S. Abdullah ◽  
A.A. Arifin ◽  
A. Othman ◽  
A.K. Ariffin ◽  
N.A.N. Mohamed

In this present paper, the two square cross-section pultruded composite tubes E-glass reinforced polyester unfilled and polyurethane hybrid foam-filled subjected to oblique load are investigated and examined experimentally. The oblique angles were varied from 5 to 20 with an increment of every 5 degree. The bottom base platen of clamped specimen was adjusted inclination angle of loading direction with respect to the tube axis. During the experimental observation, three characteristic crushing stages were identified as initial peak load stage, progressive crushing stage and compaction zone stage. The pultruded composite tube wall-thicknesses of at 3 mm were examined, and the effects of crushing behaviors and failure modes were analyzed and discussed. Results showed that the tube’s energy absorption capability was affected significantly by varying of oblique loading. It is also found that as the filling polyurethane foam into pultruded E-glass reinforced polyester composite square tube increases the amount of specific absorbed energy than the empty tubes.


2014 ◽  
Vol 638-640 ◽  
pp. 109-114
Author(s):  
Xian Guo Ye ◽  
Kai Nan Yang ◽  
Xun Chong ◽  
Qing Jiang

Mechanical properties of joint between superimposed slabs have a remarkable effect on the bending performance of the whole slab. To study the bending performance of superimposed slabs with different forms of joint, six superimposed slabs were designed and produced. Based on the static loading experiment, load was concentrated on two three-equal-division points, bearing capacity, deformation, cracks of specimens were obtained. Whether there were lattice steel bars in the precast slab or not and different reinforcement in the joint were considered to study the bending performance. The test results show that the failure mode of slab without lattice steel bars is brittle while others are ductile. Lattice steel bars can control the development of cracks along the superposed surface, increasing the shear capacity and improving the ductility of specimens. The bearing capacity of the whole superimposed slab depends on the joint cross section. The joint would not generate a difference to the deflection curves in service condition. When reinforcement in the joint is strengthened, failure modes of slabs will be effectively improved.


Author(s):  
Imre Pozsgai ◽  
Klara Erdöhalmi-Torok

The paintings by the great Hungarian master Mihaly Munkacsy (1844-1900) made in an 8-9 years period of his activity are deteriorating. The most conspicuous sign of the deterioration is an intensive darkening. We have made an attempt by electron beam microanalysis to clarify the causes of the darkening. The importance of a study like this is increased by the fact that a similar darkening can be observed on the paintings by Munkacsy’s contemporaries e.g Courbet and Makart. A thick brown mass the so called bitumen used by Munkacsy for grounding and also as a paint is believed by the art historians to cause the darkening.For this study, paint specimens were taken from the following paintings: “Studio”, “Farewell” and the “Portrait of the Master’s Wife”, all of them are the property of the Hungarian National Gallery. The paint samples were embedded in a polyester resin “Poly-Pol PS-230” and after grinding and polishing their cross section was used for x-ray mapping.


Author(s):  
Huixian Wu ◽  
James Cargo ◽  
Huixian Wu ◽  
Marvin White

Abstract The integration of copper interconnects and low-K dielectrics will present novel failure modes and reliability issues to failure analysts. This paper discusses failure modes related to Cu/low-K technology. Here, physical failure analysis (FA) techniques including deprocessing and cross-section analysis have been developed. The deprocessing techniques include wet chemical etching, reactive ion etching, chemical mechanical polishing and a combination of these techniques. Case studies on different failure modes related to Cu/low k technology are discussed: copper voiding, copper extrusion; electromigration stress failure; dielectric cracks; delamination-interface adhesion; and FA on circuit-under-pad. For the cross-section analysis of copper/low-K samples, focused ion beam techniques have been developed. Scanning electron microscopy, EDX, and TEM analytical analysis have been used for failure analysis for Cu/low-K technology. Various failure modes and reliability issues have also been addressed.


2021 ◽  
Vol 11 (9) ◽  
pp. 4043
Author(s):  
Aleksandar Landović ◽  
Miroslav Bešević

Experimental research on axially compressed columns made from reinforced concrete (RC) and RC columns strengthened with a steel jacket and additional fill concrete is presented in this paper. A premade squared cross-section RC column was placed inside a steel tube, and then the space between the column and the tube was filled with additional concrete. A total of fourteen stub axially compressed columns, including nine strengthened specimens and five plain reinforced concrete specimens, were experimentally tested. The main parameter that was varied in the experiment was the compressive strength of the filler concrete. Three different concrete compression strength classes were used. Test results showed that all three cross-section parts (the core column, the fill, and the steel jacket) worked together in the force-carrying process through all load levels, even if only the basic RC column was loaded. The strengthened columns exhibited pronounced ductile behavior compared to the plain RC columns. The influence of the test parameters on the axial compressive strength was investigated. In addition, the specimen failure modes, strain development, and load vs. deformation relations were registered. The applicability of three different design codes to predict the axial bearing capacity of the strengthened columns was also investigated.


2021 ◽  
Vol 28 (1) ◽  
pp. 139-152
Author(s):  
Teng Huang ◽  
Dongdong Zhang ◽  
Yaxin Huang ◽  
Chengfei Fan ◽  
Yuan Lin ◽  
...  

Abstract In this study, the flexural bearing capacity and failure mechanism of carbon fiber-reinforced aluminum laminate (CARALL) beams with a double-channel cross-section and a 3/2 laminated configuration were experimentally and numerically studied. Two types of specimens using different carbon fiber layup configurations ([0°/90°/0°]3 and [45°/0°/−45°]3) were fabricated using the pressure molding thermal curing forming process. The double-channel CARALL beams were subjected to static three-point bending tests to determine their failure behaviors in terms of ultimate bearing capacity and failure modes. Owing to the shortcomings of the two-dimensional Hashin failure criterion, the user-defined FORTRAN subroutine VUMAT suitable for the ABAQUS/Explicit solver and an analysis algorithm were established to obtain a progressive damage prediction of the CFRP layer using the three-dimensional Hashin failure criterion. Various failure behaviors and mechanisms of the CARALL beams were numerically analyzed. The results indicated that the numerical simulation was consistent with the experimental results for the ultimate bearing capacity and final failure modes, and the failure process of the double-channel CARALL beams could be revealed. The ultimate failure modes of both types of double-channel CARALL beams were local buckling deformation at the intersection of the upper flange and web near the concentrated loading position, which was mainly caused by the delamination failure among different unidirectional plates, tension and compression failure of the matrix, and shear failure of the fiber layers. The ability of each fiber layer to resist damage decreased in the order of 90° fiber layer > 0° fiber layer > 45° fiber layer. Thus, it is suggested that 90°, 0°, and 45° fiber layers should be stacked for double-channel CARALL beams.


2020 ◽  
Vol 4 (4) ◽  
pp. 182
Author(s):  
Luciano Ombres ◽  
Salvatore Verre

In the paper, the bond between a composite strengthening system consisting of steel textiles embedded into an inorganic matrix (steel reinforced grout, SRG) and the concrete substrate, is investigated. An experimental investigation was carried out on medium density SRG specimens; direct shear tests were conducted on 20 specimens to analyze the effect of the bond length, and the age of the composite strip on the SRG-to-concrete bond behavior. In particular, the tests were conducted considering five bond length (100, 200, 250, 330, and 450 mm), and the composite strip’s age 14th, 21st, and 28th day after the bonding. Test results in the form of peak load, failure modes and, bond-slip diagrams were presented and discussed. A finite element model developed through commercial software to replicate the behavior of SRG strips, is also proposed. The effectiveness of the proposed numerical model was validated by the comparison between its predictions and experimental results.


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