reaction force

In this project there is an example where reaction forces are found using the finite
element method. Firstly, it was solved with manually algebraic solution, then the result was
reached using the ANSYS program and the results of the two solution methods were
compared.
The finite element method, which has a history of 60 years, in recent years the use of
finite element analysis (FEA) as a design tool has grown rapidly. The finite element method is
a numerical procedure that can be used to obtain solutions to a large class of engineering
problems involving stress analysis, heat transfer, electromagnetism, and fluid flow. Easy-touse, comprehensive packages such as ANSYS, a general-purpose finite element computer
program, have become common tools in the hands of design engineers. This project is created
to assist analysis engineers of finite element modeling to gain a clear understanding of the
basic concepts. The example that is solved using ANSYS shows in detail how to use ANSYS
to model and analyses a truss analysis of an engineering problem.
In the first section, fundamentals about the finite element method and simple
definitions of matrix solutions used in analysis solutions are given. In addition to this section,
the use of the MatLab program in the finite element method is explained. In the second
section, the classification and properties of trusses and statically solving methods of truss
problems are given. The formulations and definitions required for the solution of trusses with
the finite element method are included in this section. In the third chapter, the manual solution
of determining the reaction forces of a truss structure under loaded forces using the finite
element method is given. In the fourth section, the example for which reaction forces were
found was modeled on ANSYS and solved by the program. In the final section, the results of
the example for which reaction forces were found by manually and the ANSYS Static
Structural module were compared and the consistency between the results was examined.

The Discrete Element Method (DEM) is applied to predict draft forces of a simple implement in cohesionless granular material. Results are compared with small-scale laboratory tests in which the horizontal force is measured at a straight blade. This study is focused on the ...

ABSTRACT In clinical practice, postural stability is commonly evaluated by scored balance performance of body sway on a platform. In this work, a platform with reaction force measurement is realized for postural balance analysis. A Microsystems based on microcontroller was built in order to drive the instrumentation and a graphical user interface has also realized. After calibration, experimentation test of postural balance conducted by subject has been carried.

Objective Walking is one of the most important activities of daily living that plays a vital role in the lives
of the elderly population and can help improve their physical and mental health. Especially, the survey of
ground reaction force (GRF) during walking with different speeds between young and old adults results
in better perception of essential mechanisms of speed regulation during walking. Thus, the purpose of
this study was to examine the effects of age and walking speeds on vertical GRF in younger and older
adults.
Materials & Methods The subjects of this study included 15 younger and 15 older men with a mean age
of 26.46 and 70.33 years, respectively. All the subjects were healthy and randomly selected. A-10-meters
walking path was considered along the laboratory, and a three-axis Kistler Force plate was placed in the
middle of the track. The distance of walking start line to force plate was 4 meters. Each subject walked
this 10-meters path with self-selected (100%), slow (80%) and fast (120%) speeds. The vertical GRF during
walking stance phases including weight acceptance or first peak phase (FZ1), midstance or depth
phase (FZ2), and heel off or second peak phase (FZ3) were measured by the Force plate at 200-Hz frequency.
The data were analyzed by ANOVA with repeated measures and Bonferroni tests.
Results The results showed that the effects of age (P=0.002) and speed (P=0.001) on the mean vertical
GRF are significant. Also, the interaction effect of age and speed on the mean vertical GRF was significant
(P=0.013). According to the Bonferroni test, in both age groups, the mean vertical GRF was significantly
different between different speeds (P<0.01). Moreover, at 100% (P=0.036) and 120% (P=0.002) speeds,
there were significant differences between younger and older adults. At slow speed, there was no significant
difference in GRF components (FZ1, FZ2, and FZ3) between the two age groups (p>0.05). At
self-selected and fast speeds, there were significant differences in FZ1 and FZ3 between the two groups
(p<0.01) while there was no significant difference regarding FZ2 (p>0.05). In addition, there were significant
differences at FZ1 and FZ3 between different speeds (p<0.01).
Conclusion In summary, the results of the present study showed that during walking with self-selected
and fast speeds, the reaction forces of weight acceptance and heel off phases were significantly different
between younger and older adults, but there was no significant difference in the reaction force of midstance
phase. Moreover, in both age groups, there were significant differences among walking different
speeds in the reaction forces of weight acceptance and heel off phases. It seems that lower extremity
muscles strengthening in the older adults can increase walking speed and decrease falling risks and functional
disabilities of these people.