Experimental Analysis of Aluminum Alloy Section Bars and their Mortise and Tenon Joints under Bending Load

2011 ◽  
Vol 415-417 ◽  
pp. 2338-2344
Author(s):  
Xin Shen Huang ◽  
Qun Gao ◽  
Zhi Jian Zong

Different laid modes of aluminum alloy section bars and their mortise and tenon joints were bending tested, and their mechanical properties were compared, in order to research on the influence that forming a mortise and tenon joint brought to the original bars. Opening a hole laterally and inserting another shorter bar in the hole changed the bending properties and energy absorption capacity of the original bar. In horizontal laid mode, the mortise and tenon joint was weaker than the original bar when bearing bending load, but it was stronger in vertical laid mode. Weld beads of the mortise and tenon joints were strong enough to maintain the structure integrality before the main section bars were destroyed by load.

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 249
Author(s):  
Przemysław Rumianek ◽  
Tomasz Dobosz ◽  
Radosław Nowak ◽  
Piotr Dziewit ◽  
Andrzej Aromiński

Closed-cell expanded polypropylene (EPP) foam is commonly used in car bumpers for the purpose of absorbing energy impacts. Characterization of the foam’s mechanical properties at varying strain rates is essential for selecting the proper material used as a protective structure in dynamic loading application. The aim of the study was to investigate the influence of loading strain rate, material density, and microstructure on compressive strength and energy absorption capacity for closed-cell polymeric foams. We performed quasi-static compressive strength tests with strain rates in the range of 0.2 to 25 mm/s, using a hydraulically controlled material testing system (MTS) for different foam densities in the range 20 g/dm3 to 220 g/dm3. The above tests were carried out as numerical simulation using ABAQUS software. The verification of the properties was carried out on the basis of experimental tests and simulations performed using the finite element method. The method of modelling the structure of the tested sample has an impact on the stress values. Experimental tests were performed for various loads and at various initial temperatures of the tested sample. We found that increasing both the strain rate of loading and foam density raised the compressive strength and energy absorption capacity. Increasing the ambient and tested sample temperature caused a decrease in compressive strength and energy absorption capacity. For the same foam density, differences in foam microstructures were causing differences in strength and energy absorption capacity when testing at the same loading strain rate. To sum up, tuning the microstructure of foams could be used to acquire desired global materials properties. Precise material description extends the possibility of using EPP foams in various applications.


Author(s):  
Bojan Poletanovic ◽  
Katalin Kopecsko ◽  
Ildikó Merta

The aim of this study was to examine the influence of flax fibre protection with the linseed oil and a matrix modification with cement substitution with metakaolin (in 10wt% and 15wt%) on the mechanical properties of cement-based mortars under severe environmental conditions of freeze/thaw cycles. Cement-based mortars (with the dimension of 40x40x160 mm3) were reinforced by 10mm long discrete flax fibres (Linumusitatissimum) and exposed to 51 freeze/thaw cycles under laboratory condition. Their compressive and flexural strengths, as well as specific energy absorption capacity were measured after freeze/thaw cycles and compared to the results of mortars cured for same time in water. Under freeze/thaw cycles mortars reinforced with linseed oil-treated fibres showed the same range of degradation of the compressive and flexural strengths, however, a more pronounced degradation of energy absorption capacity compared to non-treated fibre reinforced mortars was observed. The matrix modification, by partial cement substitution with metakaolin showed optimistic results under freeze/thaw cycles. The compressive strength when cement was partially substituted with metakaolin (in both dosages) increased whereas the flexural strength was slightly lower in case of 10wt% substitution and markedly lower under higher (15wt%) cement substitution. The most relevant is that the decrease of the energy absorption capacity of the fibre reinforced mortar was completely prevented when cement was substituted with metakaolin. It is shown that the energy absorption of the non-treated fibre reinforced mortars increases by 27% when cement was substituted with metakaolin (both 10wt% and 15wt%).


Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4304
Author(s):  
Miroslaw Ferdynus ◽  
Patryk Rozylo ◽  
Michal Rogala

The paper presents the results of numerical tests of impact and energy absorption capacity of thin-walled columns, subjected to axial impact loading, made of aluminum alloy, and having a square cross-section and spherical indentations on their lateral surfaces. The numerical models were validated using an experiment that was conducted on the Instron CEAST 9350 High Energy System drop hammer. Material properties of the applied aluminum alloy were determined on the basis of a static tension test. The crushing behavior of the columns and some crashworthiness indicators were investigated. On the basis of the results of the conducted analyses, conclusions were drawn about the most beneficial design/constructional variants in terms of achieved crashworthiness parameters.


2007 ◽  
Vol 158 (6) ◽  
pp. 166-175 ◽  
Author(s):  
Matthias Kalberer ◽  
Martin Ammann ◽  
Martin Jonsson

Among others, the protective effect of the forest against natural hazards is mostly co-determined through the mechanical stability of the trees. Despite this, there is a lack of quantifiable knowledge regarding the mechanical interaction between the trees, the forest and natural hazards. With experiments conducted on spruce trees,and mechanical modelling of trees and tree trunks, the mechanical properties and the energy absorption capacity for a single tree during a rock impact were determined. It was shown that the anchorage properties correlated well with the volume of the tree stem. The four-point bending tests and the dynamic impact tests enabled us to determine the strength of the tree stems. Furthermore, the obtained values for the strength of the tree stems were strongly affected by the wood quality and sometimes deviated substantially from the established material properties of dried wood used for buildings. The behavior of trees when impacted by rocks could be simulated with full-scale impact tests and the energy absorption capacity quantified. These experiments gave important knowledge of how to analyze the interaction between natural hazards, trees and forests,with the focus on Norway spruce. However, to quantify the protection effect of the forest against natural hazards,more experiments on different tree species are required.


Alloy Digest ◽  
1995 ◽  
Vol 44 (7) ◽  

Abstract ALUMINUM ALLOY 201.0 is a structural casting alloy available as sand, permanent mold and investment castings. It is used in structural casting members, applications requiring high tensile and yield strengths with moderate elongation, and where high strength and energy-absorption capacity are needed. This datasheet provides information on composition, physical properties, and elasticity as well as creep and fatigue. It also includes information on high temperature performance as well as casting, heat treating, machining, joining, and surface treatment. Filing Code: AL-336. Producer or source: Various aluminum companies.


Author(s):  
H Geramizadeh ◽  
S Dariushi ◽  
S Jedari Salami

The current study focuses on designing the optimal three-dimensional printed sandwich structures. The main goal is to improve the energy absorption capacity of the out-of-plane honeycomb sandwich beam. The novel Beta VI and Alpha VI were designed in order to achieve this aim. In the Beta VI, the connecting curves (splines) were used instead of the four diagonal walls, while the two vertical walls remained unchanged. The Alpha VI is a step forward on the Beta VI, which was promoted by filleting all angles among the vertical walls, created arcs, and face sheets. The two offered sandwich structures have not hitherto been provided in the literature. All models were designed and simulated by the CATIA and ABAQUS, respectively. The three-dimensional printer fabricated the samples by fused deposition modeling technique. The material properties were determined under tensile, compression, and three-point bending tests. The results are carried out by two methods based on experimental tests and finite element analyses that confirmed each other. The achievements provide novel insights into the determination of the adequate number of unit cells and demonstrate the energy absorption capacity of the Beta VI and Alpha VI are 23.7% and 53.9%, respectively, higher than the out-of-plane honeycomb sandwich structures.


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