• Structural Engineering and Mechanics
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• v.54 no.5
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• pp.937-953
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• 2015

This paper investigates the load model for single footfall trace of human walking. A large amount of single person walking load tests were conducted using the three-dimensional gait analysis system. Based on the experimental data, Fourier series functions were adopted to model single footfall trace in three directions, i.e. along walking direction, direction perpendicular to the walking path and vertical direction. Function parameters such as trace duration time, number of Fourier series orders, dynamic load factors (DLFs) and phase angles were determined from the experimental records. Stochastic models were then suggested by treating walking rates, duration time and DLFs as independent random variables, whose probability density functions were obtained from experimental data. Simulation procedures using the stochastic models are presented with examples. The simulated single footfall traces are similar to the experimental records.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.04a
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• pp.127-134
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• 1999

Vibration problem occurring at the metal deck floor system not only reduces the serviceability of a building but also reduces the usability of a floor system. Most problem occurring at the metal deck floor results from the human movement such as walking and running. However the vibration induced by running does not occur continuously except the special case. therefore the floor vibration due to walking was only considered on this paper,. Vibration occurring due to human walking was measured and the corresponding load function was derived through the Fast Fourier Transform(FFT)

• Structural Engineering and Mechanics
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• v.63 no.6
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• pp.847-856
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• 2017

Excessive vibrations can occur in long-span structures such as floors or footbridges due to occupant?s daily activity like walking and cause a so-called vibration serviceability issue. Since 1970s, researchers have proposed many human walking load models, and some of them have even been adopted by major design guidelines. Despite their wide applications in structural vibration serviceability problems, differences between these models in predicting structural responses are not clear. This paper collects 19 popular walking load models and compares their effects on structure?s responses when subjected to the human walking loads. Model parameters are first compared among all these models including orders of components, dynamic load factors, phase angles and function forms. The responses of a single-degree-of-freedom system with various natural frequencies to the 19 load models are then calculated and compared in terms of peak values and root mean square values. Case studies on simulated structures and an existing long-span floor are further presented. Comparisons between predicted responses, guideline requirements and field measurements are conducted. All the results demonstrate that the differences among all the models are significant, indicating that in a practical design, choosing a proper walking load model is crucial for the structure?s vibration serviceability assessment.

• KIEAE Journal
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• v.8 no.1
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• pp.105-110
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• 2008

Most high rise buildings have been constructed with steel structure systems with metal deck floors and concrete topping. Since the mass of the metal deck floor system is relatively thinner than that of the concrete floor system and due to the larger span compared to other floor systems, vibration serviceability problems are frequently occurred. Most of vibration problems are induced by the movement of humans. A walking load function was proposed for the better estimation of composite deck floor vibration based on site measurements in this paper.

• Journal of Korean Physical Therapy Science
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• v.18 no.4
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• pp.81-85
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• 2011

Purpose : The purpose of this study was to investigate the changing plantar foot pressure by the backpack load of 0, 10, 15, and 20% of their body weight while level walking in flat foot and so to recommend suitable backpack weight limitations for flat foot subjects. Method : 14 young flat foot subjects($24.29{\pm}2.16yrs$) participated in this study. the subjects were assigned to carry backpack load and there was four level walking modes : (1) unloaded walking(0%), (2) 10% body weight(BW) load, (3) 15% BW load and (4) 20% BW load. Repeated ANOVA was used to compare each region data of foot according to different backpack weight. Results : As backpack load became increased, the contact area of midfoot was significantly increased, and contact area of forefoot and rearfoot were significantly decreased. maximum pressure at each region during walking tended to be greater as the load increased, but a significant difference was found only for the heel medial and lateral regions Conclusion : Based on this data, the weight of backpack could influenced structure and function of the foot in flat foot.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.1
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• pp.65-72
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• 2003

The objective of this study is to estimate the frequency characteristics of group walking loads based on the information of measured responses. At first, dynamic properties such as natural frequencies and modes are obtained from input/output relation for building structures by heel drop test. Second, a method to estimate group walking loads by the transfer functions from measured responses to group walking loads is proposed. The method turned out to estimate the group walking loads accurately. Higher modes could be important in estimating the amplitude of group walking loads with the information of single walking load.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.414-421
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• 2001

Recently, the damping effect of building structures are greatly reduced because the use of non-structures members as like curtain wall are decreased and large open space are in need for the service of buildings. Assembly and office buildings with a lower natural frequency have a higher possibility of experiencing excessive vibration induced by human activities as like jumping, running and walking. These excessive vibration make the occupants uncomfortable and the serviceability deterioration. The common method of application of walking loads for the vibration analysis of structures subjected to walking loads is to inflict a series unit walking load and a periodic function at a node. But this method could not consider the moving effect of walking. In this study, natural frequency and damping ratio of plate structure are evaluated by heel drop tests. And new application of equivalent walking loads are introduced for vibration analysis of real slab system subjected to walking loads. The response obtained from the numerical analysis are compared well to the results measured by experimental tests. It is possible to efficiently analyze the vibration of floor which is subjected to walking loads by applying equivalent walking loads.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.1
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• pp.173-188
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• 2002

In General, the measured loads and load-time function suggested by Bachmann iota walking are used for vibration analysis of structures subjected to footstep loads. It is not easy to measure walking loads because they we influenced by various parameters. Therefore, it is needed to model the walking loads that can be applied to structure analysis. Parameter study is used for the walking loads having various walking frequency for vibration analysis of structures under walking loads. In this study, walking loads were measured directly by using a force plate within two load cells, and the parameters of the walking loads were analyzed. The measured walking loads are decomposed into harmonic loads by using the Fouler series. Functional relationship between the walking frequency and the Fourier coefficients can be derived from the coefficients of harmonic loads obtained by the decomposition process, and the walking loads were formulated. It is possible to apply the venerated walking loads easily or conveniently by the proposed equation to the analysis of a structure subjected to walking loads.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.5
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• pp.188-202
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• 2004

This research was designed to investigate biomechanical aspects of the evolution based on the hypothesis of dynamic cooperative interactions between the locomotion pattern and the body shape in the evolution of human bipedal walking The musculoskeletal model used in the computer simulation consisted of 12 rigid segments and 26 muscles. The nervous system was represented by 18 rhythmic pattern generators. The genetic algorithm was employed based on the natural selection theory to represent the evolutionary mechanism. Evolutionary strategy was assumed to minimize the cost function that is weighted sum of the energy consumption, the muscular fatigue and the load on the skeletal system. The simulation results showed that repeated manipulations of the genetic algorithm resulted in the change of body shape and locomotion pattern from those of chimpanzee to those of human. It was suggested that improving locomotive efficiency and the load on the musculoskeletal system are feasible factors driving the evolution of the human body shape and the bipedal locomotion pattern. The hypothetical evolution method employed in this study can be a new powerful tool for investigation of the evolution process.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.8 no.2
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• pp.25-31
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• 2010

Purpose : The purpose of this study was to investigate knee muscle strength, balance, and proprioception by walking while giving weight to the ankle joint at a load of 0%, 10%, and 15% gradient on a treadmill. Methods : Twenty-four subjects were divided into three groups. Group A walked on a 0% gradient while giving weight to the ankle joint as a load. Group B walked on a 10% gradient while giving weight to the ankle joint as a load. Group C walked on a 15% gradient while giving weight to the ankle joint as a load. This was performed three times per week for four weeks. The walking speed was set at 4km/hour and the walking time was set at 20 minutes. Measurements were performed before and after the experiment. Biodex medical system and Balance system SD were used as measuring instruments. Results : There was no significant difference between the gradients in muscle strength, balance and proprioception. However, there were differences in pretest and posttest measurements for muscle strength, balance and proprioception in each gradient. In particular, the gradient of 10% showed a significant difference. Conclusion : According to the results of this study, to use a 10% gradient is effective when walking while giving weight to the ankle joint as a load.