scholarly journals Advances on the Fragmentation-Energy Fan Concept and the Swebrec Function in Modeling Drop Weight Testing

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1262
Author(s):  
Finn Ouchterlony ◽  
José A. Sanchidrián ◽  
Ömürden Genç

The breakage index equation (BIE), or t10 model from drop weight testing (DWT) data for rocks and ores is used in the design of crushers and mills. Such models are becoming increasingly difficult to visualize as the number of variables increases. The so-called double fan BIE, combined with the Swebrec distribution’s accurate description of the sieving curves, is applied to the modelling of drop-weight test fragmentation. The key parameters are geometric properties visible in the fan plot; slopes of straight lines and their point of convergence. The ability of the double fan BIE to reproduce DWT data had been previously established for 8 rocks with 480 DWT data sets. Here the fidelity of the double fan BIE is further evaluated for 18 new materials, based on 281 data sets. The fidelity of the double fan BIE with three fan lines is on par with the fidelity of the current state-of-the-art models for the new materials. Besides the breakage index equation, the new double fan BIE’s t10 equation produces, without additional parameters or fitted constants, the general breakage surface equation tn for an arbitrary n value as a bonus. The specific sieving curve for any combination of particle size and impact energy is also contained in the same formula. The result is an accurate, compact and transparent model.

2016 ◽  
Vol 715 ◽  
pp. 33-38
Author(s):  
Jonas A. Pramudita ◽  
Masashi Kato ◽  
Yuji Tanabe

Skin laceration injury caused by a penetration of small curvature edge frequently occurs in a domestic accident. An assessment method for this injury is necessary in order to develop a safer manufactured product. To assess the risk of skin laceration injury in a penetration accident, a skin simulant made from silicone rubber was proposed. However, mechanical responses of this skin simulant under dynamic penetration loading have not yet been investigated. In this study, a drop weight penetration test device was developed in order to simulate penetration accidents under impact velocities of over 1 m/s. The device was then used for investigating the dynamic responses of skin simulant against several blades with different tip curvature radii. Load, penetration depth, impulse and energy at rupture were then determined from the test results. Load and penetration depth at rupture increased with the increase of tip curvature radius of the blades. Furthermore, the drop weight test result showed larger response compared to the quasi-static test result which might be caused by the viscous effect and the polymer characteristics such as cross-linking of the skin simulant.


1996 ◽  
Vol 69 (3) ◽  
pp. 253-261 ◽  
Author(s):  
A. Moitra ◽  
P.R. Sreenivasan ◽  
S.K. Ray ◽  
S.L. Mannan

2015 ◽  
Vol 1106 ◽  
pp. 225-228 ◽  
Author(s):  
Stanislav Rehacek ◽  
Petr Hunka ◽  
David Citek ◽  
Jiri Kolisko ◽  
Ivo Simunek

Fibre-reinforced composite materials are becoming important in many areas of technological application. In addition to the static load, such structures may be stressed with short-term dynamic loads or even dynamic impact loads during their lifespan. Impact loading of structural components produces a complex process, where both the characteristics of the design itself and the material parameters influence the resultant behavior. It is clear that fibre reinforced concrete has a positive impact on increasing of the resistance to impact loads. Results of two different impact load tests carried out on drop-weight test machine are presented in this report.


2006 ◽  
pp. 107-115
Author(s):  
Angelika Spalek ◽  
Gerd Reisner ◽  
Ewald Werner ◽  
Andreas Pichler ◽  
Peter Stiaszny

2020 ◽  
Vol 18 (4) ◽  
pp. 371-384 ◽  
Author(s):  
Paul Nicholas ◽  
Gabriella Rossi ◽  
Ella Williams ◽  
Michael Bennett ◽  
Tim Schork

Robotic 3D printing applications are rapidly growing in architecture, where they enable the introduction of new materials and bespoke geometries. However, current approaches remain limited to printing on top of a flat build bed. This limits robotic 3D printing’s impact as a sustainable technology: opportunities to customize or enhance existing elements, or to utilize complex material behaviour are missed. This paper addresses the potentials of conformal 3D printing and presents a novel and robust workflow for printing onto unknown and arbitrarily shaped 3D substrates. The workflow combines dual-resolution Robotic Scanning, Neural Network prediction and printing of PETG plastic. This integrated approach offers the advantage of responding directly to unknown geometries through automated performance design customization. This paper firstly contextualizes the work within the current state of the art of conformal printing. We then describe our methodology and the design experiment we have used to test it. We lastly describe the key findings, potentials and limitations of the work, as well as the next steps in this research.


Author(s):  
Mehdi Akhondizadeh ◽  
Masoud Rezaeizadeh

Effects of specimen size and ball size on the breakage throughput under the impact loading are investigated using a drop-weight test machine. Samples are square-shaped building stones ranging 20–60 mm in width and 22–256 g in mass. They include granite, marble, and two types of travertine with the thickness of 15 mm. The impact energies, up to 160 J, are achieved by falling balls in a drop-weight test machine. Several steel balls with the diameter of 60, 84, 96, and 120 mm have been used as an impactor. The ball size is a parameter whose effect on the breakage throughput is investigated here. Results show that the larger specimens have better breakage than the smaller ones at the same specific impact energy. It is also indicated that, at constant specific impact energy, the smaller balls behave more efficiently than the larger balls.


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