TY  - JOUR
A1  - Pham, Phu Tinh
A1  - Staat, Manfred
T1  - FEM-based shakedown analysis of hardening structures
JF  - Asia Pacific journal on computational engineering
N2  - This paper develops a new finite element method (FEM)-based upper bound algorithm for limit and shakedown analysis of hardening structures by a direct plasticity method. The hardening model is a simple two-surface model of plasticity with a fixed bounding surface. The initial yield surface can translate inside the bounding surface, and it is bounded by one of the two equivalent conditions: (1) it always stays inside the bounding surface or (2) its centre cannot move outside the back-stress surface. The algorithm gives an effective tool to analyze the problems with a very high number of degree of freedom. Our numerical results are very close to the analytical solutions and numerical solutions in literature.
Y1  - 2014
U6  - http://dx.doi.org/10.1186/2196-1166-1-4
SN  - 2196-1166 (E-Journal)
IS  - 1
SP  - Article No. 4
PB  - SpringerOpen
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Pfaff, Raphael
T1  - Braking distance prediction for vehicle consist in low-speed on-sight operation: a Monte Carlo approach
JF  - Railway Engineering Science
N2  - The first and last mile of a railway journey, in both freight and transit applications, constitutes a high effort and is either non-productive (e.g. in the case of depot operations) or highly inefficient (e.g. in industrial railways). These parts are typically managed on-sight, i.e. with no signalling and train protection systems ensuring the freedom of movement. This is possible due to the rather short braking distances of individual vehicles and shunting consists. The present article analyses the braking behaviour of such shunting units. For this purpose, a dedicated model is developed. It is calibrated on published results of brake tests and validated against a high-definition model for low-speed applications. Based on this model, multiple simulations are executed to obtain a Monte Carlo simulation of the resulting braking distances. Based on the distribution properties and established safety levels, the risk of exceeding certain braking distances is evaluated and maximum braking distances are derived. Together with certain parameters of the system, these can serve in the design and safety assessment of driver assistance systems and automation of these processes.
KW  - Freight rail
KW  - Shunting
KW  - Braking curves
KW  - Brake set-up
KW  - Driver assistance system
Y1  - 2023
U6  - http://dx.doi.org/10.1007/s40534-023-00303-7
SN  - 2662-4753 (eISSN)
SN  - 2662-4745 (Print)
VL  - 31
IS  - 2
SP  - 135
EP  - 144
PB  - SpringerOpen
ER  -