Influence of tyre inflation pressure on whole-body vibrations transmitted to the operator in a cut-to-length timber harvester

Journal of Low Frequency Noise, Vibration and Active Control

Boileau

et al. 2006

Laboratory-based whole-body vibration studies often involve complex experimental designs, dozens of vibration exposures and multiple sessions. Shortening the test vibration duration would increase experimental efficiency by permitting more trials in the same time period. This study evaluated reported discomfort based on different sinusoidal vibration durations and amounts of rest between successive vibrations. Ten subjects were exposed to four blocks of vibration trials (15/20 second vibration and 5/10 second rest durations). Each block of 37 trials included repeated single axis, planar, and 6 degree of freedom multi-axial vibrations. These repeated trials were analysed to evaluate whether discomfort varied between the different blocks. We did not observe any statistically significant differences in discomfort between the different vibration and rest durations. This finding is useful for designing future vibration experiments. Part II of this study evaluates the relationship between discomfort and vibration exposure.

Section: Introductionmentioning

confidence: 99%

Multi-Axis Sinusoidal Whole-Body Vibrations: Part I — How Long Should the Vibration and Rest Exposures Be for Reliable Discomfort Measures?

Dickey

Journal of Low Frequency Noise, Vibration and Active Control

Boileau

et al. 2006

“…A number of studies conducted on mobile machines have assessed chassis vibration [10,13,[15][16][17]22,[27][28][29]. Vibration exposure measurements were collected in accordance with ISO 2631-1 procedures from 1978 or 1997, and relevant information from these studies can be found in Tables V-IX.…”

Section: Discussionmentioning

confidence: 99%

“…Several factors affect WBV exposure such as the axis, magnitude and frequency of the vibrations [1,9], duration [8,10,11], axle suspension [12], driving speed [13,14], seat type [11], terrain [14,15] and tire inflation pressure [16]. While many factors affect vibration attenuation such as tires, wheel suspension, and chassis isolation/suspension, most frequently WBV attenuation attempts focus on the operator seat [12].…”

Section: Introductionmentioning

confidence: 99%

Quantification of 6-Degree-of-Freedom Chassis Whole-Body Vibration in Mobile Heavy Vehicles Used in the Steel Making Industry

Conrad

Journal of Low Frequency Noise, Vibration and Active Control

Jack

et al. 2012

Whole-body vibration (WBV) of mobile machines used in the steel making industry has not previously been quantified in six-degrees-of-freedom (6DOF). The purpose of this paper was to quantify 6DOF vibrations during the daily operating tasks of 5 commonly used mobile machines types used in the steel making and metal smelting industries. Vibration data were recorded from the chassis of five commonly used mobile machines using a MEMSense MAG3 triaxial accelerometer & gyroscope (MEMSense, SD, USA), and analyzed using custom MatlabTM code. Elevated values were observed at the chassis for crest factors, peak running root mean squared accelerations, and vibration total values, resulting in ISO 2631-1 (1997) comfort predictions ranging from Uncomfortable to Extremely Uncomfortable. Vibration dominant frequencies were generally between 1 and 8Hz. A second peak which occurred at approximately 27 Hz was observed for each vehicle in almost all axes. Occurring at a frequency that has the potential to produce negative health effects, this second peak was probably caused by the engine idling or running at low speeds. Field vibration profiles from this study have been used as inputs to a 6DOF robot for use in a corresponding laboratory study designed to optimize seat selection thus allowing the steel making and other similar industries to select operator seats based on industry specific field vibration characteristics.

“…WBV exposure can be uncomfortable and has been linked to back [5][6][7], neck and shoulder pain [8,9]. While many factors affect vibration attenuation such as tires [10], wheel suspension [11], driving speed [12,13] and terrain [13,14], most frequently WBV vibration attenuation attempts focus on the operator seat [11]. The seat is the primary method of vibration transmission from the chassis of the vehicle to the operator and is often mounted to the chassis using a non-permanent fixation method.…”

Section: Introductionmentioning

confidence: 99%

Reducing whole-body vibration through field vibration tested heavy equipment seat retrofitting

Hope

Conrad

et al. 2016

OER

Abstract. BACKGROUND: Heavy mobile equipment operation exposes operators to whole-body vibration (WBV) through the seat. The decision of which seat to retrofit a machine with is usually done statically. OBJECTIVE: To report on the third phase of a three phase project designed to intelligently retrofit seats in heavy mobile machines with the purpose of reducing machine operator WBV exposure. METHODS: Three slag pot haulers were retrofitted with a 6801 Isringhausen seat in which the seat pan cushion was retrofitted with Skydex TM seating material. Vibration dose values (weighted for health), vibration total values (weighted for comfort) and Seat Effective Amplitude Transmissibility were determined from field measurements. RESULTS: WBV was reduced from the first field study to below the upper boundary of the ISO 2631-1 (1997) health guidance caution zone and comfort weighted vibration total values were reduced to the second lowest discomfort rating. CONCLUSIONS: Steel making and other similar industries have been provided with information to more efficiently retrofit existing machines.