A simplified ABS numerical model: Comparison with HIL and full scale experimental tests

2008 ◽  
Vol 86 (13-14) ◽  
pp. 1494-1502 ◽  
Author(s):  
F. Cheli ◽  
A. Concas ◽  
E. Giangiulio ◽  
E. Sabbioni
2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Rasool Ahmadi ◽  
Omid Rashidian ◽  
Reza Abbasnia ◽  
Foad Mohajeri Nav ◽  
Nima Usefi

An experimental test was carried out on a 3/10 scale subassemblage in order to investigate the progressive collapse behavior of reinforced concrete (RC) structures. Investigation of alternative load paths and resistance mechanisms in scaled subassemblage and differences between the results of full-scale and scaled specimens are the main goals of this research. Main characteristics of specimen response including load-displacement curve, mechanism of formation and development of cracks, and failure mode of the scaled specimen had good agreement with the full-scale specimen. In order to provide a reliable numerical model for progressive collapse analysis of RC beam-column subassemblages, a macromodel was also developed. First, numerical model was validated with experimental tests in the literature. Then, experimental results in this study were compared with validated numerical results. It is shown that the proposed macromodel can provide a precise estimation of collapse behavior of RC subassemblages under the middle column removal scenario. In addition, for further evaluation, using the validated numerical model, parametric study of new subassemblages with different details, geometric and boundary conditions, was also done.


Author(s):  
Abdulkadir Zirek ◽  
Petr Voltr ◽  
Michael Lata ◽  
Jaroslav Novák

Advanced antislip control methods are available these days. However, due to increasing requirements with regard to demand and emerging technologies in the field of railways, further research on antislip control is required. Therefore, in this study, an antislip control algorithm, based on a sliding mode control, is proposed to stabilize the slip and improve the traction ability of a full-scale tram wheel test stand. To verify the validity of the control scheme, a numerical model of a tram wheel test stand has been generated using the MATLAB editor. The Freibauer and Polach contact theory has been employed to determine the coefficient of adhesion and adhesion force. Moreover, the derived algorithm was implemented on a full-scale tram wheel test stand. Experiments were carried out under several wheel–roller surface conditions. The results of the refined numerical model are in good agreement with the experimental data obtained from the tram wheel test stand. For both the experimental tests and the numerical model, the response of the proposed control algorithm is rather satisfactory with regard to the stabilization of the slip and improvement of the traction ability.


Author(s):  
M. Mongiardini ◽  
J. D. Reid

Numerical simulations allow engineers in roadside safety to investigate the safety of retrofit designs minimizing or, in some cases, avoiding the high costs related to the execution of full-scale experimental tests. This paper describes the numerical investigation made to assess the performance of a roadside safety barrier when relocated behind the break point of a 3H:1V slope, found on a Mechanically Stabilized Earth (MSE) system. A safe barrier relocation in the slope would allow reducing the installation width of the MSE system by an equivalent amount, thus decreasing the overall construction costs. The dynamics of a pick-up truck impacting the relocated barrier and the system deformation were simulated in detail using the explicit non-linear dynamic finite element code LS-DYNA. The model was initially calibrated and subsequently validated against results from a previous full-scale crash test with the barrier placed at the slope break point. After a sensitivity analysis regarding the role of suspension failure and tire deflation on the vehicle stability, the system performance was assessed when it was relocated into the slope. Two different configurations were considered, differing for the height of the rail respect to the road surface and the corresponding post embedment into the soil. Conclusions and recommendations were drawn based on the results obtained from the numerical analysis.


2015 ◽  
Vol 36 ◽  
pp. 98-105 ◽  
Author(s):  
Laura Biganzoli ◽  
Gaia Racanella ◽  
Lucia Rigamonti ◽  
Roberto Marras ◽  
Mario Grosso

Author(s):  
Athanasios Vratsikidis ◽  
Dimitris Pitilakis ◽  
Anastasios Anastasiadis ◽  
Anastasios Kapouniaris

2018 ◽  
Author(s):  
Adel Albaba ◽  
Massimiliano Schwarz ◽  
Corinna Wendeler ◽  
Bernard Loup ◽  
Luuk Dorren

Abstract. This paper presents a Discrete Element-based elasto-plastic-adhesive model which is adapted and tested for producing hillslope debris flows. The numerical model produces three phases of particle contacts: elastic, plastic and adhesion. The model capabilities of simulating different types of cohesive granular flows were tested with different ranges of flow velocities and heights. The basic model parameters, being the basal friction (ϕb) and normal restitution coefficient (ϵn), were calibrated using field experiments of hillslope debris flows impacting two sensors. Simulations of 50 m3 of material were carried out on a channelized surface that is 41 m long and 8 m wide. The calibration process was based on measurements of flow height, flow velocity and the pressure applied to a sensor. Results of the numerical model matched well those of the field data in terms of pressure and flow velocity while less agreement was observed for flow height. Those discrepancies in results were due in part to the deposition of material in the field test which are not reproducible in the model. A parametric study was conducted to further investigate that effect of model parameters and inclination angle on flow height, velocity and pressure. Results of best-fit model parameters against selected experimental tests suggested that a link might exist between the model parameters ϕb and ϵn and the initial conditions of the tested granular material (bulk density and water and fine contents). The good performance of the model against the full-scale field experiments encourages further investigation by conducting lab-scale experiments with detailed variation of water and fine content to better understand their link to the model's parameters.


Author(s):  
Liviu Crudu ◽  
Radu Bosoancă ◽  
Dan Obreja

The evaluation of ship resistance is of paramount importance having a decisive impact on the economic performances and efficiency depending on mission. If new IMO requirements through the Energy Efficiency Design Index (EEDI) are taken into account the necessity to have more and more accurate tools capable to consider the influences of different parameters became mandatory. The availability of towing tank facilities and the full scale trials are the practical means in order to be able to confirm the accuracy of theoretical formulations and to define the limits of CFD applications. Based on the results of the towing tank tests, a direct comparison with the results provided by classical methods and CFD computations can be systematically can be performed. On the other hand, the influences of the modifications operated on the fore part of the ship aretheoretically evaluated and compared with the towing tank results. Consequently, the paper is focused on the comparison of the results evaluated using different tools which have been carried out for a Chemical Tanker built by Constanta Shipyard Romania.


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