Vibration Dose Value Research Articles

Enhancement of rider comfort by magnetorheological elastomer based damping treatment at strategic locations of an electric two wheeler

The vibrations generated in the two-wheeled vehicles like motorcycles due to road irregularities such as cracks, potholes, and bumps on the road cause discomfort for the rider as well as the pillion. These vibrations are reported to cause lower back pains, musculoskeletal effects, fatigue, and long-term health issues. Particularly, electric two-wheelers are more susceptible to these vibrations caused by the road and need attention. This paper presents an innovative technique for the reduction of vibrations at prominent locations in the electric two-wheeler to improve the rider’s comfort. All measured accelerations are about vertical direction (along z-axis as per ISO 2631-1 standard). Passive and Semi-active damping treatments namely, Room temperature vulcanizing Silicone rubber and Magnetorheological elastomer (MRE) were applied on the test vehicle at strategic locations of vibration. Both were compared for their effectiveness in reducing the vibrations. Results showed that MRE based damping technique proved better vibration isolation at the strategic locations. The weighted root mean square acceleration as well as vibration dose values were found to decrease with the help of damping treatments thus improving the rider’s overall comfort level.

Long-term loading effect on vibration performance of CLT floors: An 896-day monitoring study

Timber, a viscoelastic material, undergoes deformation over time when exposed to sustained loads, a process known as creep. Its rising popularity as a construction material, especially for timber floors, is notable. However, the influence of creep on the dynamic characteristics of timber floors, such as their natural frequency and vibration response, is not well studied. This research focused on how long-term loading (creep) affects the vibration behaviours of a cross-laminated timber (CLT) floor. A full-scale CLT floor was constructed in a lab and subjected to long-term loading using sandbags. Over 896 days, the centroid point deflection and environmental conditions (temperature and relative humidity) were monitored. Human-induced vibration tests were carried out at the beginning, throughout, and at the end of this period. The vibration response, measured in terms of the Vibration Dose Value (VDV), was assessed at various stages of long-term loading. The findings showed a moderate positive correlation between the creep deflection and environmental conditions. The fundamental frequency slightly increased over time due to creep, and a general decrease in VDV was observed as the creep advanced.

Improvement of Dynamic Characteristics of Purpose-Built Vehicles Using Semi-Active Suspension System.

The diversification of mobility into services such as smart stores and conference rooms has accelerated the development of purpose-built vehicles (PBVs)-vehicles designed for specific purposes that utilize an extended electric vehicle chassis and autonomous driving technology. Despite the standards on speed bump dimensions stipulated by the National Land Transportation Act of the Republic of Korea, real-world speed bumps feature varying widths and heights that deviate from these standards. In this study, a velocity equation was derived via regression analysis to achieve the desired dynamic characteristics for a PBV passing over speed bumps with varying shapes through two types of semi-active suspension control: proportional-integral-differential (PID) and linear-quadratic-regulator (LQR). For a cargo-transport PBV, the PID and LQR controllers increased the velocity by 23.74% and 50.74%, respectively, under different speed bump widths and by 19.44% and 38.31%, respectively, under different speed bump heights. Moreover, an analysis of the vibration dose value (VDV), an indicator of ride comfort, revealed that the VDVs calculated using the velocity equation were within an acceptable error range of 10% above the target VDV. These findings provide insights into the speed control required for different types of autonomous PBVs to ensure ride comfort, as well as minimize the driving duration, depending on the specific purpose of the vehicle.

A Critical Assessment of Boundary Limits of Health Risks Associated with WBV Exposure Based on Field Studies on LHD Vehicles in Indian Underground Coal Mines

Purpose: The mining sector plays a pivotal role in meeting global resource demands, necessitating the extensive use of heavy earth-moving machinery (HEMM). Among these, load-haul-dump (LHD) mining vehicles are vital but expose operators to whole-body vibration (WBV) and shocks during their duties. Research indicates potential health risks associated with occupational WBV exposure, including musculoskeletal disorders. Evaluating these risks typically employs ISO 2631-1:1997, which, however, has limitations in addressing long-term exposure and shock effects. Methods: This study quantifies the health risks of LHD operators in Indian underground coal mines using ISO 2631-5:2018 and compares it to ISO 2631-1:1997. The methods for risk quantification from WBV vary between the two standards, leading to a comprehensive comparison. In addition, a cross-sectional study was undertaken to assess self-reported musculoskeletal pain among LHD operators. Results: The results were compared in accordance with frequency-weighted root mean square (RMS) values, vibration dose values (VDV), daily compressive dose (Sd A), and the risk of injury (RA) factor. The assessment using A(8), VDV, Sd A, and RA produced diverse evaluations, influencing varying perspectives on occupational health despite significant risks. ISO 2631-5:2018 consistently suggested a lower health risk for LHD operators as opposed to ISO 2631-1:1997. Seat effective amplitude transmissibility (SEAT) values showed amplification of vibration in the range of 4-8 Hz. Self-reported musculoskeletal pain indicated the prevalence of discomfort among operators. Conclusion: The study emphasizes a cautious approach when interpreting results and shaping guidelines to ensure sustainable development through the well-being of mining industry workers.

Effect of partition walls on the vibration serviceability of cross-laminated timber floors

The current standards need more specific serviceability criteria for Cross-Laminated Timber (CLT) floors. This paper presents a comprehensive analysis of a relevant case study in Norway, which presented unexpectedly high accelerations in the CLT floors after construction. The lack of a sufficiently detailed design process resulted in the poor vibration performance of the floors, which partially compromised their functionality. The paper thoroughly investigates and discusses the experimental dynamic characterization of seven CLT floors within the considered building. The authors estimated the modal parameters and serviceability metrics based on both Eurocode 5 (EC5) and the new draft version of it. Specifically, the authors compared the analytical predictions of the fundamental frequency and the root mean square acceleration against the corresponding experimental estimations. Using a sensor-roving approach, a dense sensor configuration was adopted to describe seven floors’ mode shapes and serviceability metrics. These metrics include mean square acceleration and Vibration Dose Value. The scenarios examined in this study shed light on the significance of partition walls, a factor not considered in the practical design for serviceability verifications. The presence of partition walls can enhance the vibration comfort of timber floors by providing a stiffening effect, leading to a significant increase in the first fundamental frequency. A parametric finite element model was developed using OpenSeesPy to investigate this phenomenon further. The model, firstly validated against selected experimental results, is employed to assess the influence of partition walls on floor dynamics. The model predicts the increase in the first frequency caused by randomly generated partition walls. The paper proposes an empirical expression calibrated on the simulated data to estimate the relative increment of the floor’s fundamental frequency based on the partition walls’ layout. This formulation can be included in the analytical expression enclosed in the EC5 draft to predict the fundamental frequency of timber floors.

Assessing the Influence of RMS and VDV on Analysis of Human Perception of Vibrations in Buildings Caused by Selected Sources of Traffic

This research paper delves into the nuanced effects of traffic-induced vibrations on human comfort and perception within residential and commercial buildings. By prioritizing the influence of vehicle types—including metro trains, trams, and cars—over their speed or mass, the study presents a novel perspective on addressing vibrational comfort. Conducted in the urban context of Warsaw’s metro line construction, this investigation employs a rigorous methodology, utilizing both the Root Mean Square (RMS) and Vibration Dose Value (VDV) analytical methods to quantify vibrational impacts. The findings illuminate the distinct contributions of various transportation modes to the perceived vibrations, offering significant insights into the complex relationship between the Human Perception of Vibration Index (HPVI) and VDV values. It underscores the necessity of integrating a multifaceted consideration of vehicle type, operational dynamics, and urban infrastructure in the strategic planning and design of buildings. Such a holistic approach is essential for mitigating the adverse effects of transportation-induced vibrations, thereby enhancing the quality of life and well-being of urban inhabitants.

Cycling on rough roads: a model for resistance and vibration

Minimising opposing forces is a matter of interest to most cyclists. These forces arise from passage through air (‘drag’) and interaction with the road surface (‘resistance’). Recent work recognises that resistance forces arise not only from the deformation of the tyre (‘rolling resistance’) but also from irregularities in the road surface (‘roughness resistance’), which lead to power dissipation in the body of the rider through vibration. The latter effect may also have an adverse impact on human health. In this work we offer a quantitative theory of roughness resistance and vibration that links these effects to a surface characterisation in terms of the International Roughness Index (IRI). We show that the roughness resistance and the Vibration Dose Value (or VDV, the usual vibration dosage metric) can be expressed in terms of elementary formulae. The roughness resistance depends only on the vertical stiffness of the bicycle and the roughness index. Surprisingly, other apparently relevant parameters, such as physiological characteristics of the bicycle rider and other features of the bicycle, do not enter. For roads of moderate roughness, roughness resistance is larger than rolling resistance. For very rough roads, roughness resistance is larger than aerodynamic drag. So only on roads of high quality (in most jurisdictions, accounting for less than 10% of the total) can roughness resistance be ignored. Roughness resistance can be mitigated by reducing the vertical stiffness of the bicycle. In common with other recent reports, we find that almost any cycling activity will breach public health guidelines relating to Vibration Dose Value.

Spherical Cap Studs: A novel speed bump alternative to reduce discomfort with effective speed reduction

Objective The aim of this study is to assess the potential of Spherical Cap Studs (SCS) as a substitute for conventional speed bumps, with a focus on limiting two wheeler speed while minimizing discomfort to riders by comparing the speed reduction capabilities and discomfort levels associated with SCS and speed bumps. Methods The study uses experimental approach to compare the speed limiting ability and discomfort caused to rider by the proposed SCS and a standard speed bump. Speed profiles were developed for two wheelers passing over both SCS and speed bump. The parameter employed to compare speed profiles is the Mean Absolute Percentage Difference (MAPD), offering valuable insights into how effectively the two traffic calming measures reduce two wheeler speeds. To compare discomfort, the study calculates the ‘Vibration Dose Value’ (VDV) experienced by riders when traversing both speed bump and SCS. Additionally, ‘Static Compressive Stress’ (Se) applied to the spinal cord is also calculated in both scenarios. Results The analysis of speed profiles reveals an MAPD value of 13.70% indicating that SCS exhibits speed reduction capabilities comparable to traditional speed bump. In terms of discomfort, the VDV for two wheelers passing over a speed bump is measured at 5.92 m/s1.75, whereas the VDV for SCS is found to be 5.16 m/s1.75. Similarly, the Static Compressive Stress (Se) experienced at a speed bump is 0.60 MPa, in contrast to the 0.33 MPa recorded for SCS. This data underscores a noteworthy 12.8% reduction in VDV and a substantial 45.57% reduction in Se. Conclusion The study’s findings support the potential adoption of SCS as an effective alternative to conventional speed bumps for controlling two wheeler speeds. SCS demonstrate a speed reduction capability similar to that of traditional speed bumps while significantly alleviating discomfort for riders. SCS is expected to be a promising solution for traffic calming purposes in various settings, such as markets, residential areas, institutional campuses, and parking lots.

Design and development of SiteHive MEMS based system for real-time vibration monitoring

Construction projects need to proactively manage their works that may cause vibration impacts to nearby structures and stakeholders. Risks of vibration include cosmetic and structural damage to buildings and threats to human comfort. The advent of MEMS accelerometers offers significant opportunities to improve on traditional vibration monitoring practices based on geophones. Geophones measure velocity which preclude acceleration based measurements and calculations like vibration dose value (the measure for human comfort), groundborne noise, and auto-levelling. The inability to capture these results means additional monitoring devices are required to capture all key measurements. MEMS-based vibration monitoring systems can be much cheaper, smaller, and more power efficient than traditional vibration monitoring systems. This enables easier installation, greater mobility, and more monitoring to be conducted. SiteHive has worked extensively with the National Measurement Institute (NMI) and the University of Technology Sydney (UTS) to test and validate the efficacy of the MEMS-based accelerometers and develop a calibration system for MEMS-based devices. This paper will outline the design research and findings that have gone into this development, results from field testing, and details on the value offered by this innovation.

Cross-laminated timber (CLT) floor serviceability under multi-person loading: Impact of beam–panel connections

Due to the lightweight nature of timber, vibration serviceability is a crucial issue in the design of timber floors. The purpose of this study is to investigate how beam–panel connections affect the vibration serviceability of cross-laminated timber (CLT) floors subjected to multi-person loading. Cyclic tests were carried out to determine the mechanical behaviour of steel beam–CLT panel connections with various screws sizes (diameters and lengths). A numerical model of a CLT floor was developed to determine the response to human-induced vibrations with different screw configurations (sizes and spacing). The results showed that the dynamic characteristics of the floor were slightly impacted by the screw size. However, as the spacing between screws reduced, the fundamental natural frequency increased by 4.3% and the vibration dose value (VDV) of the floor decreased by 38.3%. A theoretical model was introduced to predict the fundamental natural frequency of a CLT floor system. In addition, a design method for predicting the vibration serviceability, in terms of VDV, of low-frequency CLT floors was proposed.

Ride comfort analysis of vehicle seat suspension systems: A co-simulation study

In this study, the vehicle seat suspension system installed with a semi-active magnetorheological (MR) damper is excited by the power spectral density (PSD) and its vibration control performance is evaluated using finite element analysis (FEA). The control system receives the velocity of the sprung and unsprung mass from the seat mounting locations and calculates the desired controllable damping forces available from MR damper. The effectiveness of the control systems is demonstrated by adopting ride quality evaluation method. To predict a better ride comfort and ride quality, co-simulation methodology is utilized considering the dynamic behavior of the real-world seat system. In this case, the multi-body dynamics and control system are coupled by solving the mechanical equations and the control logic. Then, the computed damping force is exchanged between the dynamics and controller in an iterative manner by passing state variables. The simulation results achieved from co-simulation methodology associated with the controller are analyzed by comparing with ISO 2631-1. The co-simulation results studied using vibration dose value (VDV), crest factor (CF) and seat effective amplitude transmissibility (SEAT) in terms of percentage improvement were found to be 44.33%, 26.66% and 17.65% respectively which were better than that for the passive suspension for a random rough road profile. Modified skyhook controller delivers superior performance for vibration suppression of the vehicle seat suspension as compared to other control policies. The application of co-simulation methodology can reduce time and cost for the development of a semi-active seat suspension system.

Measurement Time in the Evaluation of Whole-Body Vibration: The Case of Mechanized Wood Extraction with Grapple Skidder

The grapple skidder is a self-propelled forestry machine that is used for the extraction of trees in wood harvesting—commonly used in full tree systems. Moving this machine can expose operators to occupational hazards of physical origin, among which whole body vibration stands out. However, the measurement of this risk agent does not have a standard measurement time, being performed for periods of approximately 30 min—disregarding the time of the daily workday. In view of this, it was analyzed whether occupational exposure to whole body vibration transmitted to grapple skidder operators using different measurement times complies with the guidelines for preventative purposes. Thus, measurements of whole-body vibration were carried out along three orthogonal axes over a period of one hour and over a daily workday of eight hours—by which were measured the daily (8 h) vibration exposure for the l-axis and the vibration value. The acceleration values in the three evaluated axes were higher for the daily working day, denoting the influence of the measurement time. In addition, the vibration dose value resulted in values above the action limit for both evaluations; however, the daily workload was highlighted—indicating the presence of higher vibration peaks over a longer measurement time. Thus, the assertiveness and influence of measurement times over the daily working day for whole-body vibration transmitted to grapple skidder operators is evidenced.

Vibration Control and Ride Comfort Analysis of a Full Car with a Driver Model Using Big-Bang Big-Crunch Optimized FLC

The main motive of the active suspension system is to enhance the ride comfort by suppressing the vibrations induced due to road irregularities. The actuator is getting more significance in the automotive industry due to its superior ride comfort for passengers. In this study, an eight Degrees of Freedom (DOF) full car with a driver model is considered for the ride comfort analysis (ISO2631 Standard) and vibration control. The real road terrain is not uniform in nature. Hence an effective intelligent control technology is required to improve the quality of travel. Initially, a conventional Proportional Integral and Derivative (PID) controller is designed for the system. Then a Fuzzy Logic Controller (FLC) is designed for the 8 DOF vehicle model to control the unwanted vibration produced in the vertical and angular directions. The FLC is designed with suitable firing rules, membership functions, and scaling factors using MATLAB/Simulink 2019 environment. The performance of FLC is further enhanced by the Big Bang Big Crunch (B3C) optimization technique, and it can suppress vibrations when the vehicle is travelling over bumpy and imperfect random road terrain as per ISO 8608. The Root Mean Square (RMS), Frequency Weighted RMS (FWRMS), and Vibration Dose Value of seat acceleration are the performance indices to investigate the potency of B3C-tuned FLC against the PID controller, FLC and passive suspension system.

Prescribed Performance Control-Based Semi-Active Vibration Controller for Seat Suspension Equipped with an Electromagnetic Damper

Seat suspension plays a vital role in improving riding comfort and protecting drivers’ health. This paper develops semi-active seat suspension that equips a controllable electromagnetic damper (EMD) and proposes a prescribed performance control-based semi-active vibration controller with experimental validation. The semi-active EMD mainly consists of a permanent magnet synchronous motor, a ball screw, a three-phase rectifier, and a controllable external resistor, which can vary its damping from 90 to 800 N·s/m by tuning the controllable external resistor in real-time. The EMD is applied to seat suspension, and a semi-active controller is proposed for the EMD seat suspension. In order to control the seat suspension vibration, a prescribed performance method is applied to obtain a desired control force and then a force-tracking strategy is designed to make the EMD track the desired control force. Finally, the semi-active seat suspension with the proposed controller is tested in experiments with different vibration conditions. The semi-active seat suspension performs excellently for the bump, sine wave and random vibration. The root mean square (RMS) acceleration, the frequency-weighted RMS acceleration and the acceleration’s fourth power vibration dose value were reduced by 17.5%, 39.9%, and 25.4%, respectively, in the random vibration, compared with a passive system.

Evaluation and prediction method of railway passenger long-term vibration comfort under complex operating conditions

Vibration contributes large increases in railway passenger discomfort during long-term sitting. Discomfort caused by vibration may differ in different operation conditions. This paper conducted field measurements to investigate the interrelationships between the three. Participants completed a 240-min train journey with their whole-body vibration, subjective comfort ratings and train operating parameters being recorded. A large correlation was observed between the estimated vibration dose value and subjective comfort. The relationship that vibration magnitude significantly increases with increasing the train speed and tunnel density was also found and quantified. A vibration exposure limit of 2.08 m/s1.75 corresponding to the boundary between subjective ratings of comfortable and discomfortable was obtained. Based on the exposure limit and the quantified relationship, a vibration comfort prediction method that can calculate the passenger’s maximum tolerance time under a given operation condition was proposed and may help in determining the optimal operating speed and tunnels distribution to alleviate vibration discomfort. Practitioner summary: Similar to the guide to effect of vibration on health in current standard, a vibration exposure limit regarding comfort was provided for reference when assessing long-term vibration comfort. Meanwhile, a prediction method was proposed for determining the best train operating speed and tunnels distribution, thereby alleviating railway passengers’ vibration discomfort.

Takagi–Sugeno Fuzzy Model-Based Control for Semi-Active Cab Suspension Equipped with an Electromagnetic Damper and an Air Spring

Variable damping shock absorbers have received extensive attention for their efficient vibration reduction performance, and air springs have also been widely used in high-end commercial vehicles due to their nonlinear stiffness characteristics. This paper presents a novel semi-active cab suspension integrated with an air spring and a variable damping electromagnetic damper (A-EMD). The electromagnetic damper (EMD) prototype was designed, manufactured and tested. Then, due to the interference of nonlinear stiffness characteristics of the air spring with the controller in the subsequent design, the Takagi–Sugeno fuzzy method was adopted to segmentally linearize its nonlinearity, based on which an H∞ state feedback semi-active controller was designed to control the EMD to generate variable damping force. Furthermore, a Luenberger state observer was designed to provide immeasurable state parameters for the controller. Numerical simulations were carried out to validate the effectiveness of the proposed approaches, and the results show that the proposed control strategy can significantly improve the ride comfort of the A-EMD system. The vibration dose value (VDV) acceleration under the bump road and the frequency-weighted acceleration root mean square (FWA-RMS) under the random road decreased by 36.05% and 19.77%, respectively, compared with the passive suspension system.

Vibration Assessment of a 12-kW Self-Propelled Riding-Type Automatic Onion Transplanter for Transplanting Performance and Operator Comfort

Vibration assessment of upland crop machinery under development is essential because high vibrational exposures affect machine efficiency, service life of components, degradation of the working environment, and cause health risks to the operator. It is intensively assessed for automobiles as well as large off-road agricultural vehicles (i.e., tractors). However, it is mostly overlooked in the case of the small or medium riding-type upland utility vehicles. Therefore, the vibration exposures of a 12-kilowatt self-propelled riding-type automatic onion transplanter were measured and evaluated to assess the performance of onion transplantation and the operator’s comfort in this study. Different types of driving surfaces, operating statuses (static and driving), and load conditions were considered to analyze the vibration exposure. The precision of transplantations was evaluated while operating the transplanter on the soil surface with different driving speeds and load conditions. Tri-axial accelerometers and a LabVIEW-coded program were used for data acquisition. The vibrational exposures were evaluated based on ISO standards, and power spectral density (PSD) was estimated to assess the major frequencies. According to the statistical analysis, the daily exposure value (A(8)) and the vibration dose value (VDV) varied from 10 to 15 ms−2 and 20 to 31 ms−1.75, respectively, which exceeded the ISO 2631-1 standards (i.e., A(8): 1.15 ms−2 and VDV: 21 ms−1.75). The calculated health risk factor (RA) was moderate. Moreover, a high weighted acceleration (around 8 ms−2) was observed on the seedling conveyor belt, which might result in missing seedlings during transplanting. The vibration exposures of the developed onion transplanter need to be minimized following the ISO standards, and vibration reduction would also improve the market competitiveness.

Parametric study of rider’s comfort in a vehicle with semi-active suspension system under transient road conditions

Considering that many Nigerian roads are untarred, the effect of frequent plying of these untarred roads on passengers and the expected performance of suspension system of vehicles are important for health and safety reasons. This is significant because the transmission of vibration associated with suspension systems are dependent on the frequency spectrum of the road input, and the nature of the suspension system and the vehicle seating arrangement that is producing the vibration. Thus, this study focuses on the discomfort experienced by passengers based on parametric study of vehicle with semi-active suspension system under transient road conditions. The modeling of the of semi-active vehicle suspension system properties are contrived on the mass- spring damper system for 4 degree-of–freedom half- car model integrated with 3 degrees of freedom human-seat arrangement. Using vehicle parameters, the severity of ride discomfort experienced by the passenger as the vehicle traversed transient road conditions (i.e., traversing obstruction) was evaluated in terms of the vibration dose value (VDV). Results of simulation based on the parametric studies are presented and the vibration dose values evaluated to show the dependence of vehicle ride comfort on the characteristics of the various elements of the vehicle suspension such as stiffness and damping characteristics. The result showed that the variation of sprung mass and suspension stiffness of the vehicle had more significant effects on passenger discomfort than the variation of the unsprung mass. The parametric study also revealed that suspension stiffness affects the suspension working space as the vehicle traversed transient road condition.

Commercial straight-deck trailer vibration and microclimate conditions during market-weight pig transport during summer

The objective of this study was to collect and quantify three-axis acceleration data from six locations within commercial pig transport trailers during summer. Two trucks with straight-deck trailers transporting two loads per day were observed for 5 consecutive days (N= 20). Accelerometers were placed under the floor of each trailer’s top and bottom decks (DECs) in the center of three sections (SECs): fore, middle, and aft. Data from each trailer section were processed to calculate z- and x,y-axis root mean square (RMS) values and vibration dose values (VDVs) during loading, transport, and unloading. There were no DEC × SEC interactions or SEC main effects for z-axis RMS or VDV during any transportation stage (P> 0.06). The bottom deck had a greater x,y-axis RMS than the top deck during all transportation stages (P< 0.01). The bottom deck had a greater x,y-axis VDV than the top deck during loading and transport (P< 0.03), but there was no difference (P= 0.52) during unloading. The bottom deck had a greater z-axis RMS and VDV than the top deck during loading and transport (P< 0.01), but there were no differences during unloading (P> 0.07). There were no SEC effects for x,y- and z-axis RMSs and VDVs during all transportation stages (P> 0.06). Acceleration values were compared with exposure action values (EAV; injury possible) and exposure limit values (ELV; injury likely) vibrations thresholds. Over the 5 observation days during all transport stages, a greater percentage of compartments violated both RMS and VDV thresholds in the x,y orientation (average 90%) than in the z orientation (average 76%). Overall, these data indicate that bottom decks experience greater three-axis vibrations than top decks in straight-deck trailers and that pigs on bottom decks may experience greater discomfort during transportation that could contribute to fatigue or the non-ambulatory condition.

2 Vibration Profiles of Commercial Straight-Deck Trailers Transporting Market-Weight Pigs During Summer

Abstract The objective was to collect and quantify three-axis acceleration data from locations within commercial transport trailers shipping market weight pigs during summer. Two trucks and straight-deck trailers, owned and operated by a single producer, were observed during two loads per day for five consecutive days. Three-axis accelerometers were placed under top and bottom deck floors in the center of the fore, center, and aft compartments. Z-axis and combined x- and y-axis data were processed to generate root-mean-square (RMS) values and vibration dose values (VDV) during loading, trailer movement, and unloading. At all periods of the trip and both sets of axis data, there were no Deck × Area interactions (P > 0.11) for RMS and VDV values. During loading and movement, the bottom deck had greater z-axis RMS and VDV values than the top deck (P < 0.01), but there was no difference (P = 0.07) during unloading. There were no Area effects for z-axis RMS and VDV values during all time periods (P > 0.06). During all periods, the top deck had greater x,y-axis RMS values than the bottom deck (P < 0.02). During loading and movement, the bottom deck had greater x,y-axis VDV values than the top deck (P < 0.03), but there was no difference (P = 0.52) during unloading. There were no Area effects for x,y-axis RMS and VDV values during all time periods (P > 0.07). Individual trip RMS and VDV values were compared with exposure action values (EAV; injury possible) and exposure limit values (ELV; injury likely). At all parts of the trip, trailer RMS and VDV violated between 51% and 99% EAV and ELV thresholds. These data indicate top and bottom decks vibrate differently and pigs experience vibrations that may contribute to fatigued pig syndrome or the non-ambulatory condition.