Effect of Laser Forming on the Energy Absorbing Behavior of Metal Foams

2021 ◽  
pp. 1-29
Author(s):  
Tom Zhang ◽  
Yubin Liu ◽  
Nathan Ashmore ◽  
Wayne Li ◽  
Y. Lawrence Yao
Keyword(s):  
Metal Foam ◽  
Laser Forming ◽  
Compression Tests ◽  
Forming Process ◽  
Static Compression ◽  
Closed Cell ◽  
Similarities And Differences ◽  
Energy Absorbing ◽  
The Impact ◽  
Quasi Static Compression

Abstract Metal foam is light in weight and exhibits an excellent impact absorbing capability. Laser forming has emerged as a promising process in shaping metal foam plates into desired geometry. While the feasibility and shaping mechanism has been studied, the effect of the laser forming process on the mechanical properties and the energy absorbing behavior in particular of the formed foam parts has not been well understood. This study comparatively investigated such effect on as-received and laser formed closed-cell aluminum alloy foam. In quasi-static compression tests, attention paid to the changes in the elastic region. Imperfections near the laser irradiated surface were closely examined and used to help elucidate the similarities and differences in as-received and laser formed specimens. Similarly, from the impact tests, differences in deformation and specific energy absorption were focused on, while relative density distribution and evolution of foam specimens were numerically investigated.

Effect of Laser Forming on the Energy Absorbing Behavior of Metal Foams

2021 ◽  
Author(s):  
Tom Zhang ◽  
Yubin Liu ◽  
Y. Lawrence Yao
Keyword(s):  
Metal Foam ◽  
Metal Foams ◽  
Laser Forming ◽  
Test Scheme ◽  
Compression Tests ◽  
Forming Process ◽  
Band Formation ◽  
Static Compression ◽  
Energy Absorbing ◽  
The Impact

Abstract Metal foam is light in weight and exhibits an excellent impact absorbing capability. Laser forming has emerged as a promising process in shaping metal foam plates into desired geometry. While the feasibility and shaping mechanism has been studied, the effect of the laser forming process on the mechanical properties and the energy absorbing behavior in particular of the formed foam parts has not been well understood. This study comparatively investigated such effect on as-received and laser formed closed-cell aluminum alloy foam. In quasi-static compression tests, attention was paid to the changes in the elastic region. Imperfections near the laser irradiated surface were closely examined and used to help elucidate the similarities and differences in as-received and laser formed specimens. Similarly, from the impact tests, the dynamically induced deformation and crush band formation were investigated with a modified Charpy impact test scheme. Differences in specific energy absorption were studied and were related to the defects formed during laser forming process. The relative density distribution and evolution of foam specimens were numerically investigated. Laser induced imperfections lead to very minor decrease in the energy absorbing ability of the metal foam, and laser forming still remain as a viable shaping process for metal foams.

scholarly journals Laser Forming of Sandwich Panels With Metal Foam Cores

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Tizian Bucher ◽  
Steven Cardenas ◽  
Ravi Verma ◽  
Wayne Li ◽  
Y. Lawrence Yao
Keyword(s):  
Power Plants ◽  
Metal Foam ◽  
Sandwich Panels ◽  
Laser Forming ◽  
Process Conditions ◽  
Foam Core ◽  
Mechanism Analysis ◽  
Forming Process ◽  
Solar Power Plants ◽  
The Impact

Over the past decade, laser forming has been effectively used to bend various metal foams, opening the possibility of applying these unique materials in new engineering applications. The purpose of the study was to extend laser forming to bend sandwich panels consisting of metallic facesheets joined to a metal foam core. Metal foam sandwich panels combine the excellent shock-absorption properties and low weight of metal foam with the wear resistance and strength of metallic facesheets, making them desirable for many applications in fields such as aerospace, the automotive industry, and solar power plants. To better understand the bending behavior of metal foam sandwich panels, as well as the impact of laser forming on the material properties, the fundamental mechanisms that govern bending deformation during laser forming were analyzed. It was found that the well-established bending mechanisms that separately govern solid metal and metal foam laser forming still apply to sandwich panel laser forming. However, two mechanisms operate in tandem, and a separate mechanism is responsible for the deformation of the solid facesheet and the foam core. From the bending mechanism analysis, it was concluded on the maximum achievable bending angle and the overall efficiency of the laser forming process at different process conditions. Throughout the analysis, experimental results were complemented by numerical simulations that were obtained using two finite element models that followed different geometrical approaches.

On the random-based closed-cell metal foam modeling and its behavior in laser forming process

2015 ◽  
Vol 72 ◽  
pp. 53-64 ◽  
Author(s):  
Amir H. Roohi ◽  
H. Moslemi Naeini ◽  
M. Hoseinpour Gollo ◽  
M. Soltanpour ◽  
M. Abbaszadeh
Keyword(s):  
Metal Foam ◽  
Laser Forming ◽  
Forming Process ◽  
Closed Cell ◽  
Foam Modeling

scholarly journals On the relationship between force reduction, loading rate and energy absorption in athletics tracks

2017 ◽  
Vol 232 (2) ◽  
pp. 71-78 ◽  
Author(s):  
Luca Andena ◽  
Antonio Ciancio ◽  
Francesco Briatico-Vangosa ◽  
Stefano Mariani ◽  
Andrea Pavan
Keyword(s):  
Material Properties ◽  
Loading Rate ◽  
Stored Energy ◽  
Compression Tests ◽  
Static Compression ◽  
Track Geometry ◽  
Force Reduction ◽  
The Impact ◽  
The Relationship ◽  
Quasi Static Compression

In this work, finite element simulations of typical sports surfaces were performed to evaluate parameters, such as the loading rate and the energy absorbed by the surface, in relation to its characteristics (surface structure and material properties). Hence, possible relations between these quantities and the standard parameters used to characterize the shock absorbing characteristics of the athletics track (in particular, its force reduction) were investigated. The samples selected for this study were two common athletics tracks and a sheet of natural rubber. They were first characterized by quasi-static compression tests; their mechanical properties were extrapolated to the strain rate of interest and their dependence on the level of deformation was modelled with hyperelastic constitutive equations. Numerical simulations were carried out for varying sample thicknesses to understand the influence of track geometry on force reduction, loading rate and stored energy. A very good correlation was found between force reduction and the other relevant parameters, with the exception of the loading rate at the beginning of the impact.

A NONLINEAR STRAIN-DEPENDENT VARIABLE-ORDER FRACTIONAL MODEL WITH APPLICATIONS TO ALUMINUM FOAMS

Fractals ◽  
2021 ◽  
Author(s):  
WEI CAI ◽  
PING WANG
Keyword(s):  
Power Law ◽  
Variable Order ◽  
Aluminum Foams ◽  
Static Compression ◽  
Fractional Model ◽  
Comparative Results ◽  
The Impact ◽  
Strain Responses ◽  
Strain Dependent ◽  
Quasi Static Compression

In this paper, a power-law strain-dependent variable order is first incorporated into the fractional constitutive model and employed to describe mechanical behaviors of aluminum foams under quasi-static compression and tension. Comparative results illustrate that power-law strain-dependent variable order is capable of better describing stress–strain responses compared with the traditional linear one. The evolution of fractional order along with the porosities or relative densities can be well qualitatively interpreted by its physical meaning. Furthermore, the model is also extended to characterize the impact behaviors under large constant strain rates. It is observed that fractional model with sinusoidal variable order agrees well with the experimental data of aluminum foams with impact and non-impact surfaces.

Experimental investigation of the quasi-static and impact tests on the energy absorption characteristics of coupler rubber buffers used in railway vehicles

2018 ◽  
Vol 233 (9) ◽  
pp. 937-950 ◽  
Author(s):  
Shuguang Yao ◽  
Zhixiang Li ◽  
Wen Ma ◽  
Ping Xu ◽  
Quanwei Che
Keyword(s):  
Energy Absorption ◽  
Impact Velocity ◽  
High Speed ◽  
Compression Tests ◽  
Static Compression ◽  
Static Tests ◽  
Impact Tests ◽  
High Speed Trains ◽  
The Impact ◽  
Absorption Characteristics

Coupler rubber buffers are widely used in high-speed trains, to dissipate the impact energy between vehicles. The rubber buffer consists of two groups of rubbers, which are pre-compressed and then installed into the frame body. This paper specifically focuses on the energy absorption characteristics of the rubber buffers. Firstly, quasi-static compression tests were carried out for one and three pairs of rubber sheets, and the relationship between the energy absorption responses, i.e. Eabn  =  n ×  Eab1, Edissn =  n ×  Ediss1, and Ean =  Ea1, was obtained. Next, a series of quasi-static tests were performed for one pair of rubber sheet to investigate the energy absorption performance with different compression ratios of the rubber buffers. Then, impact tests with five impact velocities were conducted, and the coupler knuckle was destroyed when the impact velocity was 10.807 km/h. The results of the impact tests showed that with the increase of the impact velocity, the Eab, Ediss, and Ea of the rear buffer increased significantly, but the three responses of the front buffer did not increase much. Finally, the results of the impact tests and quasi-static tests were contrastively analyzed, which showed that with the increase of the stroke, the values of Eab, Ediss, and Ea increased. However, the increasing rates of the impact tests were higher than that of the quasi-static tests. The maximum value of Ea was 68.76% in the impact tests, which was relatively a high value for the vehicle coupler buffer. The energy capacity of the rear buffer for dynamic loading was determined as 22.98 kJ.

scholarly journals Energy Absorption of Different Cell Structures for Closed-Cell Foam-Filled Tubes Subject to Uniaxial Compression

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1579 ◽  
Author(s):  
Yang Yu ◽  
Zhuokun Cao ◽  
Ganfeng Tu ◽  
Yongliang Mu
Keyword(s):  
Energy Absorption ◽  
Absorption Efficiency ◽  
Foam Core ◽  
Aluminum Foams ◽  
Static Compression ◽  
Cell Structures ◽  
Closed Cell ◽  
Energy Absorption Efficiency ◽  
Foam Filled ◽  
Quasi Static Compression

The energy absorption of different cell structures for closed-cell aluminum foam-filled Al tubes are investigated through quasi-static compression testing. Aluminum foams are fabricated under different pressures, obtaining aluminum foams with different cell sizes. It is found that the deformation of the foam core is close to the overall deformation, and the deformation band is seriously expanded when the cell size is fined, which leads to the increase of interaction. Results confirm that the foam-filled tubes absorb more energy due to the increase of interaction between the foam core and tube wall when the foaming pressure increases. The energy absorption efficiency of foam-filled tubes can reach a maximum value of 90% when the foam core is fabricated under 0.30 MPa, which demonstrates that aluminum foams fabricated under increased pressure give a new way for the applications of foam-filled tubes in the automotive industry.

Bidirectional self-locked energy absorbing system: Design and quasi-static compression properties

2019 ◽  
Vol 144 ◽  
pp. 106366 ◽  
Author(s):  
Yang Zhao ◽  
Liming Chen ◽  
Bing Du ◽  
Houchang Liu ◽  
Baocai Chen ◽  
...  
Keyword(s):  
System Design ◽  
Static Compression ◽  
Compression Properties ◽  
Energy Absorbing ◽  
Quasi Static Compression

scholarly journals Thermally Induced Mechanical Response of Metal Foam During Laser Forming

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Tizian Bucher ◽  
Adelaide Young ◽  
Min Zhang ◽  
Chang Jun Chen ◽  
Y. Lawrence Yao
Keyword(s):  
Temperature Gradient ◽  
Mechanical Response ◽  
Metal Foam ◽  
Mechanical Performance ◽  
Image Correlation ◽  
Laser Forming ◽  
Experimental Proof ◽  
Thermally Induced ◽  
The Impact ◽  
Different Levels

To date, metal foam products have rarely made it past the prototype stage. The reason is that few methods exist to manufacture metal foam into the shapes required in engineering applications. Laser forming is currently the only method with a high geometrical flexibility that is able to shape arbitrarily sized parts. However, the process is still poorly understood when used on metal foam, and many issues regarding the foam's mechanical response have not yet been addressed. In this study, the mechanical behavior of metal foam during laser forming was characterized by measuring its strain response via digital image correlation (DIC). The resulting data were used to verify whether the temperature gradient mechanism (TGM), well established in solid sheet metal forming, is valid for metal foam, as has always been assumed without experimental proof. Additionally, the behavior of metal foam at large bending angles was studied, and the impact of laser-induced imperfections on its mechanical performance was investigated. The mechanical response was numerically simulated using models with different levels of geometrical approximation. It was shown that bending is primarily caused by compression-induced shortening, achieved via cell crushing near the laser irradiated surface. Since this mechanism differs from the traditional TGM, where bending is caused by plastic compressive strains near the laser irradiated surface, a modified temperature gradient mechanism (MTGM) was proposed. The densification occurring in MTGM locally alters the material properties of the metal foam, limiting the maximum achievable bending angle, without significantly impacting its mechanical performance.

Application of Fractional Derivatives to Modeling the Quasi-Static Response of Polyurethane Foam

2003 ◽  
Author(s):  
Rong Deng ◽  
Patricia Davies ◽  
Anil K. Bajaj
Keyword(s):  
System Identification ◽  
Polyurethane Foam ◽  
Elastic Model ◽  
Compression Tests ◽  
Static Compression ◽  
Identification Method ◽  
Dissipative Effects ◽  
Identification Technique ◽  
Nonlinear Elastic ◽  
Quasi Static Compression

A fractional derivative model of dissipative effects is combined with a nonlinear elastic model to model the response of polyurethane foam in quasi-static compression tests. A system identification method is developed based on a separation of the elastic and viscoelastic parts of the response, which is possible because of symmetries in the imposed deformation timehistory. Simulations are used to evaluate the proposed identification method when noise is present in the response. The system identification technique is also applied with some success to experimental data taken from several compression experiments on two types of polyurethane foam blocks.

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