scholarly journals Kinematics of the motorcar body side deformation process during front-to-side vehicle collision and the emergence of a hazard to car occupants

Meccanica ◽  
2021 ◽  
Author(s):  
Leon Prochowski ◽  
Mirosław Gidlewski ◽  
Mateusz Ziubiński ◽  
Krzysztof Dziewiecki
Keyword(s):  
Deformation Process ◽  
Experimental Tests ◽  
Body Part ◽  
Complex Nature ◽  
Linear Processes ◽  
Compression Phase ◽  
Body Side ◽  
Car Body ◽  
Vehicle Collision ◽  
Non Linear

AbstractThe kinematics of the process of deformation of the motorcar body side in the culminating phase of a front-to-side vehicle collision has been examined as a possible basis for analyzing and modeling the process of emergence of a hazard to car occupants during a road accident. The course of such accidents has a complex nature and their models are necessarily based on the approximation of non-linear elastoplastic characteristics of impact processes, especially during the transition from the compression phase to the restitution phase of the deformation process. For such characteristics to be obtained, a lot of experimental tests have to be carried out. This paper addresses the short-duration processes with a high degree of complexity.A front-to-side motorcar collision model has been prepared, which made it possible to analyze the process of deformation of the car body side and the emergence of a hazard and injuries to car occupants. The results of calculation of the deformation rate and range in various car body zones, velocity of the test dummy placed on driver’s seat and velocity of possible dummy’s impact against the car body side being deformed may be taken as a basis for designing effective occupant protection systems. The kinematics of the phase of vehicle contact and deformation process was modeled with taking into account results of experimental tests, including the curves characterizing the largely non-linear processes that are decisive for the deformation of the car body side. The deformation processes analyzed on these grounds showed at the same time the range of penetration of the deformed body part into the car interior, which causes a hazard to vehicle occupants. The calculation results have shown e.g. that the car body side is deformed to a depth of 0.2 m as quickly as within 0.02–0.03 s. At such a car body side deformation range, the car body part being deformed hits occupant’s body in his/her hips and pelvis area with a velocity of about 6 m/s.

The structure of non-linear processes

Tellus ◽  
1973 ◽  
Vol 25 (6) ◽  
pp. 536-544 ◽  
Author(s):  
A. Quinet
Keyword(s):  
Linear Processes ◽  
Non Linear

scholarly journals Sustainable Development Goal Drivers in Food Systems

2021 ◽  
Vol 5 ◽  
Author(s):  
Sebastian Kretschmer ◽  
Johannes Kahl
Keyword(s):  
Sustainable Development ◽  
Food Systems ◽  
Sustainable Development Goals ◽  
Food System ◽  
Driving Forces ◽  
Linear Processes ◽  
Non Linear ◽  
Development Goals ◽  
Diagnostic Framework ◽  
Primary Predictor

Interacting driving forces in food systems, resulting in cumulative driver effects and synergies, induce non-linear processes in multiple directions. This paper critically reviews the discourse on driving forces in food systems and argues that mindset is the primary predictor for food system outcomes. In the epoch of sustainable development goals (SDGs) and the Anthropocene, mindset matters more than ever. Transformative narratives are beginning to transcend the dominant social paradigm, which is still driving the food system's overall trajectory. The psychosocial portrayal of the systemic mindset found in organic food systems presented in this paper “flips the script” and hypothesizes that worldview and paradigm have the most causal linkages with unsustainable driver synergies and reversely the biggest leverage on the mitigation thereof. Borrowing from ecological economics discourses, the paper sharpens the driver definition by applying the DPSIR analytical tool as a modified diagnostic framework and modeling approach for food systems. This research sheds new light on the nature of drivers of change, which are often portrayed as almighty and inevitable trends shaping food systems. Instead, it is proposed that drivers emerge from the actors' mindset, affecting food system behavior in a non-linear way. Mindset drives reinforcing feedback loops, resulting in vicious and virtuous cycles. These driver motives manifest in subsystems and continue to drive their interaction across food system elements. Mindset acts as an encapsulated input of food systems, all the while responding to feedback and releasing new drivers. A transformation framework along leverage points of the food system is presented that features the concept of SDG drivers.

Real Time Loading Test Rig for Flight Control Actuators Under PHM Experimentation

2018 ◽  
Author(s):  
P. Chiavaroli ◽  
A. De Martin ◽  
G. Evangelista ◽  
G. Jacazio ◽  
M. Sorli
Keyword(s):  
Flight Control ◽  
Linear Models ◽  
Angular Position ◽  
Experimental Tests ◽  
Hydraulic Actuator ◽  
Loading Test ◽  
Pressure Transducers ◽  
Non Linear ◽  
Flight Controls ◽  
Servo Actuator

The article deals with the architecture, performance, and experimental tests of a test bench for servo-actuators used in flight controls. After the state of the art on the subject, the innovative architecture of the built bench is described, in which flight control actuator under test and load actuator are not in line but mounted perpendicularly. The model of the bench actuating systems is then presented, consisting of the servo-controlled hydraulic actuator, load cell, speed transducer, angular position transducer of the coupling and pressure transducers. For each of these components the nonlinear multi-physics mechatronic model is described, according to the adopted solutions. The adopted force control algorithm is discussed, showing the integrative compensation on the action line and proportional-derivative on the feedback, with speed feedforward. The experimental tests carried out on the bench under stalled conditions are also presented, whose results concerning time and frequency responses are compared with those obtained through the linearized and non-linear numerical model. Finally, the non-linear models of the flight control actuator under test, controlled in position, and of the loading servo-actuator of the bench are joined together, and the results of various simulations are described.

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