Rigid Behavior Research Articles

A Study on the Impact of Overtaking Lane-Changing Behaviour in Expressway Interchange Weaving Areas

This study investigates the overtaking lane-changing (OLC) behaviour in expressway interchange weaving areas, aiming to analyse these behaviours’ causes and potential impacts. Field data are utilised to analyse the statistical characteristics of lane-changing points and spatio-temporal utilisation in weaving areas. A modified NS model, which considers the distribution pattern of vehicle speeds, and a rigid lane-changing rule based on Gaussian distribution are proposed. Additionally, a cellular automaton simulation model is constructed to quantify the influence of OLC behaviour on traffic efficiency and spatio-temporal utilisation based on simulated data. The findings indicate that the imbalanced distribution of lane-changing points and spatio-temporal utilisation in weaving segments, caused by rigid lane-changing behaviour, is an objective factor that triggers OLC behaviour. When the traffic volume in weaving areas ranges from 500 to 1,100 pcu/5 min and the proportion of OLC behaviour is between 0.35 and 0.7, the behaviour will significantly enhance the average vehicle speeds of the outermost lane of the main road and normal rigid lane-changing (NRLC) vehicles, with increases of up to 48% and 51%, respectively. Moreover, OLC behaviour also improves the balance of spatio-temporal utilisation in weaving areas and reduces the average spatio-temporal utilisation. This study clarifies the positive impact of OLC behaviour on expressway interchange weaving areas and provides new research ideas for enhancing the efficiency of these areas.

Mechanical, thermal, and microstructure analysis of 3D printed polyolefin elastomer-acrylonitrile butadiene styrene blends for tunable mechanical properties

Fused Deposition Modeling (FDM) has emerged as a cost-effective and user-friendly technique that has garnered significant attention in recent years. However, challenges persist when printing soft materials using FDM technology. This study proposes a solution by blending a soft polyolefin elastomer (POE) with a stiffer material, acrylonitrile butadiene styrene (ABS). A comprehensive experimental investigation utilizing a direct pellet printing method was conducted to 3D print POE-ABS blends in various ratios (10%, 30%, and 50% ABS content). The study encompassed material preparation, 3D printing, SEM (Scanning Electron Microscopy) analysis, Dynamic Mechanical Thermal Analysis (DMTA), uniaxial tensile testing, and compression testing to assess the mechanical properties and energy absorption capabilities of the 3D printed blends. The results of the DMTA showed that the blends with a higher amount of ABS have a larger area under the Tan δ curve, indicating their ability to absorb more energy. The SEM images revealed that as the proportion of ABS increases, the gaps between layers and beads become smaller. The mechanical properties of the pure printed POE, such as its elongation at break and tensile strength, were 2138% and 2.83 MPa, respectively. However, as the ABS content increased, the samples exhibited more rigid behavior, with a final transition to 50/50 ratio resulting in 9.4 MPa tensile strength and 160% elongation at break. The energy absorption test demonstrated that the sample with 30% ABS content has the highest energy absorption capability among all the tested samples. This research underscores the potential of blending soft and stiff materials to tailor properties for additive manufacturing applications, emphasizing the significance of material composition in achieving desired mechanical performance, printability, and functionality in printed objects.

Effect of Fluid Paraffin on the Formulation Properties of Pressure Sensitive Adhesive Formulations Containing Diclofenac Sodium.

Understanding the relationship between the release characteristics of the active ingredient in the tape formulation and the pharmaceutical characteristics of the adhesive layer can optimize therapeutic efficacy and improve patient adherence. This study aimed to clarify the effect of liquid paraffine (LP)/styrene-isoprene-styrene (SIS) triblock copolymer ratio on pressure-sensitive adhesive (PSA) formulation properties, such as adhesive properties and drug release, with a certain amount of diclofenac sodium (DFS) and tackifier. The effects of changes in PSA composition in DFS-containing tape formulations on adhesive and drug release properties were evaluated. The viscoelasticity results showed rigid gel-like behavior at low angular frequencies regardless of the LP/SIS ratio, and deformable gel-like behavior at high angular frequencies, with a maximum plasticizing effect of LP up to an LP/SIS ratio of 3.7. The peel adhesion test results showed that peel adhesion was not affected, but indicated a decreasing trend by increasing the LP/SIS ratio in the presence of DFS. Drug release test results showed that DFS release increased up to 24h for LP/SIS ratios of up to 3.7, but decreased when the LP/SIS ratio was 6. The results of the drug permeation tests were similar to those of the drug release tests. In conclusion, it is possible to change the drug release properties by changing the amount of LP in the tape formulation; however, no definitive correlation was found between the adhesive and drug release properties.

Analytical models for predicting the moment‒rotation relationships of steel hub joints with bolted steel side plates in single-layer wood reticulated domes

A very popular and efficient pattern of joints adopted for wood reticulated domes is steel hub joints featuring end-bearing and bolt-connected wood members (EBBC joints). This type of joint shows clear semi-rigidity, which affects the rigidity and overall stability of the structures. This study developed analytical models for predicting the moment‒rotation curves of EBBC joints, considering the effect of axial compression. Specifically, two models termed the WR and WEP models, were developed assuming rigid and elastic-plastic constitutive behaviour, respectively, of the wood in the compression zone of the joint. A tri-linear model for the lateral force-slip relationship of bolt connections was derived. A formula for calculating the deformation modulus and predicting the shear failure of wood members under local compression was proposed and verified. The moment–rotation relationship of the joint was established with equilibrium and compatibility conditions. The accuracy of the analytical models was verified by comparison with a series of experimental results as well as the parametric study results obtained using a refined finite element model. It was revealed that both the WR and the WEP models can predict the moment–rotation relationships accurately for joints without axial compression, whereas for the case of non-negligible axial compression loads, the WEP model offers more accurate predictions. The analytical WEP model proposed in the current paper provides a versatile tool for general design practice to predict moment–rotation curves for traditional or novel EBBC joints.

Reported Barriers and Facilitators for Autistic Individuals, Persons with Other Intellectual and Developmental Disabilities, and Their Caregivers to Receive the COVID-19 Vaccine: A Pilot Study.

Autistic individuals and persons with other intellectual or developmental disabilities (IDD) may experience challenges in social engagement, sensory processing, and behavior rigidity. This population is more likely to face barriers to successful preventative healthcare, including vaccines, compared to neurotypical peers. Autistic individuals and persons with other IDD may be at greater risk for COVID-19 infection due to sensory dysregulation that interferes with mitigation such as wearing masks, and challenges in social communication that impose difficulties in understanding and adhering to prevention measures. Adaptations are needed to make vaccine opportunities more accessible for neurodivergent individuals. A series of seven Sensory-Friendly COVID-19 Vaccine Clinics (SFVCs) were conducted between December 2021 and August 2022 in collaboration with the A.J. Drexel Autism Institute and the Academy of Natural Sciences of Drexel University. SFVCs examined perceived barriers and facilitators to vaccine experiences, based on feedback from autistic individual/persons with IDD and their caregivers. Surveys were administered to autistic individuals/persons with IDD or their caregivers (n = 35) from the larger sample who attended the clinic; 18 participants also complete a supplemental interview. Scaled survey questions were analyzed to determine the acceptability of the SFVCs. Open-ended survey questions and interview responses were coded thematically to identify barriers, facilitators, and areas of improvement. All individuals who came to a SFVC with intent to be vaccinated were successfully administered a COVID-19 vaccine. More than 90% of participants reported that experiences at the SFVCs were positive, promoted retention, and they would recommend clinics to others. Staff clinical expertise, sensory-friendly elements, and hosting clinics at a neutral location (free from past medical history) served as facilitators to successful vaccine administration, whereas factors such as ill-equipped pharmacy staff, behavioral challenges, and logistical issues may serve as barriers. Incorporating reported barriers, facilitators, and accommodations of SFVC experiences may lead to more successful preventative healthcare processes for neurodivergent individuals.

Preparing Inclusive Early Childhood Educators (PIECE): A conceptualization of multilingualism, English learning, and inclusivity

AbstractThe purpose of this article is to share the examination of inclusivity as a paradigm for fostering authenticity and agency (Moore, 2017) among teacher candidates. This framing challenges the notion of inclusion as a tool of meritocracy used to manage learners through expectations that uphold monolingualism, decenter racial histories, and rely on rigid behavior plans. In this work, the authors interrogate the impact inclusion as assimilation has on English learners' authentic ways of knowing and being. Thus, they present a conceptualization of spaces of difference (Agbenyaga & Klibthong, 2012) within the context of an Inclusive Early Childhood Teacher Education (IECTE) program and the objectives of the Preparing Inclusive Early Childhood Educators (PIECE) project. With its rigorous coursework, clinical experiences, multi‐tiered mentorship, and practice‐based professional development, the PIECE project aims to develop inclusive early childhood educators at the preservice and in‐service levels. Infused throughout the PIECE project is an emphasis on cultivating the knowledge and skills needed to provide high‐quality instruction that improves educational outcomes for English learners (ELs). Frameworks of transformative theory and intersectionality perspectives provided the authors with a grounding for the work within the PIECE project community of learners (i.e., teacher candidates, teacher educators, and school district partners). This article summarizes critical concepts of inclusivity centered in the PIECE project work. These concepts include (1) understanding oneself to look beyond; (2) disrupting notions of normalcy and naturalized language; and (3) reconceptualizing inclusivity as a social justice act.

Conceptual shaking table tests for resilient segmental bridge columns with resettable sliding joints

The ever-increasing demand for accelerated construction of urban bridges or viaducts calls for more prefabrication with various joint schemes, while satisfying the need for seismic resilience. On the other hand, segmentation into components of various shapes and morphologies is common for multifunctional structures found in living organisms and ancient Chinese timber structures, which also inspires the development of resilient segmental bridge column design. To provide further insights into the cost-effective resilient design of precast bridge columns, this paper suggests the use of resettable sliding joints (RSJ) comprising lubricated gently-inclined joint interface with partially debonded tendon arrangement, essentially forming a hybrid sliding and rocking seismic isolation system of precast segmental structures. The deformability of the proposed design is high. Similitude analysis was conducted considering the rigid body behavior of individual segments under seismic input. It presents the conceptual shaking table testing of four 1:12 prestressed segmental column models fabricated with special three-dimensional (3D) printed plastic molds and interface treatment. A motion capture system was installed for accurate 3D displacement data acquisition and five typical major near-fault earthquake records were selected. Among all specimens, the RSJ segmental column could reach a high damping ratio of about 20 % during the tests, and it outperformed the others in many aspects: (i) a tolerable maximum top drift of about 1 %; (ii) a moderate percentage of transient rocking of about 20 %; (iii) an evenly distributed sliding displacement among all sliding joints; and (iv) negligible residual sliding drift at sliding joints. These superior attributes of RSJ segmental column are consistent under excitation of consecutive rounds of different major earthquake records, indicating high robustness as well as high seismic resilience in the design of RSJ segmental columns.

Cantilever piled-wall design criteria in cohesionless soil: a review

Purpose The design of cantilever pile walls (CPWs) presents several common challenges. These challenges include soil variability, groundwater conditions, complex loading conditions, construction considerations, structural integrity, uncertainties in design parameters and construction and monitoring costs. Accordingly, this paper is to provide a detailed literature review on the design criteria of CPWs, specifically in cohesionless soil. This study aims to present a comprehensive overview of the current state of knowledge in this area. Design/methodology/approach The paper uses a literature review approach to gather information on the design criteria of CPWs in cohesionless soil. It covers various aspects such as excavation support systems (ESSs), deformation behavior, design criteria, lateral earth pressure calculation theories, load distribution methods and conventional design approaches. Findings The review identifies and discusses common challenges associated with the design of CPWs in cohesionless soil. It highlights the uncertainties in determining load distribution and the potential for excessive wall deformations. The paper presents various approaches and methodologies proposed by researchers to address these challenges. Originality/value The paper contributes to the field of geotechnical engineering by providing a valuable resource for geotechnical engineers and researchers involved in the design and analysis of CPWs in cohesionless soil. It offers insights into the design criteria, challenges and potential solutions specific to CPWs in cohesionless soil, filling a gap in the existing knowledge base. The paper draws attention to the limitations of existing analytical methods that neglect the serviceability limit state and assume rigid plastic soil behavior, highlighting the need for improved design approaches in this context.

Characterization and Modeling of Rigid Pile Behavior

Characterization and Modeling of Rigid Pile Behavior

Numerical Investigation of the Effect of Deltoid Radius on Tensile Load in T-joints

In this study, T-shaped joints were designed from composites with different deltoid radius. For this purpose, carbon fiber woven fabrics were preferred as reinforcement elements. Then, tensile analyzes were performed on these composite T-joints. The effect of the deltoid radius on the maximum tensile load and damage behavior of the structure was examined. As a result of the analyses, fiber tensile-compression damage images occurring in the structure for each deltoid radius were obtained along with the load-displacement graph. The Hashin damage criterion was preferred for damage onset. Material Property Degradation (MPDG) method was used for damage progression in progressive damage analysis. By increasing the deltoid radius from 6 mm to 12 mm, the maximum contact load increased by approximately 10%, and by increasing it to 18 mm, the maximum contact load increased by approximately 20.11%. Fiber compression damage, spread over a wide area on the lower surface of the flange where it does not come into contact with the web, was determined to be the dominant damage type, and it was determined that this damage decreased with the increase of the deltoid radius. it was observed that as the deltoid radius increases, the T-jointed composite structure exhibits more rigid material behavior.

Hybrid equilibrium formulation with adaptive element side orientation for cohesive crack prediction

AbstractThe present article proposes an hybrid equilibrium element (HEE) formulation for the prediction of cohesive fracture formation and propagation with the crack modelled by extrinsic interface embedded at element sides. The hybrid equilibrium element formulation can model high order (quadratic, cubic and quartic) stress fields which strongly satisfy homogeneous equilibrium equations, inter‐element and boundary equilibrium equations. The HEE can implicitly model both the initially rigid behaviour of an extrinsic interface and its debonding condition with separation displacement and softening. The extrinsic interface is embedded at the element sides and its behaviour is governed by means of the same degrees of freedom of HEE (generalized stresses), without any additional degree of freedom. The proposed extrinsic cohesive model is developed in the thermodynamic framework of damage mechanics. The proposed crack propagation criterion states that crack grows when the maximum principal stress reaches the tensile strength value, in a direction orthogonal to the principal stress direction. The crack is embedded at an element side and the mesh around crack tip is adapted, by rotation of the element sides, in order to have the interface aligned to the crack growth direction. Three classic two‐dimensional problems of fracture propagation are numerically reproduced and the results compared to the experimental data or to the other numerical results.

Rigid Pavement Acceleration-Velocity Dynamic Behavior Induced by Traffic Load

Rigid Pavement Acceleration-Velocity Dynamic Behavior Induced by Traffic Load

Development of a New Vertical Dynamic Model of a Rail Vehicle for the Analysis of Ride Comfort

The rail vehicle industry wants to produce vehicles with higher speeds, to maintain and increase its market share. However, when the speed of the vehicle increases, it may have an undesirable effect on ride comfort, in terms of ride dynamics. Recent developments towards lighter and faster vehicles make the problem of ride comfort at higher speeds increasingly important. Focusing on the behavior of flexible rather than rigid body behavior should not be neglected when designing long and light car bodies. There are several approaches to incorporate body flexibility in multibody simulations and they have some superiorities and weaknesses. In this study, an efficient and accurate vertical dynamic model for the ride comfort analysis is developed and implemented in a commercial object-oriented modeling (OOM) software Dymola (2015 FD01) which uses the open-source code Modelica. This model includes car body flexibility with the assembling of a rigid body approach. The developed model is compared to a three-dimensional vehicle model in the commercial Vampire software (Pro V5.50) at different velocities. For the vertical ride comfort analysis, the ISO 2631-1 standard was used for both the developed model and the three-dimensional model. The results are presented as acceleration history and awrms—weighted r.m.s (root mean square) of accelerations—as required by the standard. The developed model has shown its feasibility in terms of its efficiency and accuracy for the vertical ride comfort analysis. The accuracy of the model is evidenced by the fact that the car body vibration level at high speeds shows minor differences compared to the results of the Vampire, which is a validated commercial software in the area of rail vehicle dynamics. The approach involving the assembly of rigid bodies is applied for the first time for high-speed trains in dynamical modelling, with flexible car bodies for ride comfort analysis. Furthermore, it can be used for parametrical studies focusing on ride comfort, thereby offering a quite beneficial framework for addressing the challenges of ride comfort analysis in high-speed rail vehicles. Improvements for and analyses of other aspects are also possible, since the optimization and other useful libraries are readily available in Dymola/Modelica.

Scrubber installation of inland container ships: Discrepancy between government and carriers

Scrubbers are the commonly used green technologies for a ship to reduce sulfur emissions. Various speed adjustment behaviors would distort the cost and desulfurization efficiency of scrubbers for ships, which causes a discrepancy between the government and the carrier to install scrubbers. This paper addresses the issue by considering three speed adjustment behaviors: rigidity, partial flexibility, and full flexibility. Under rigid behavior, the carrier maintains a constant sailing speed when adopting low-sulfur fuel oil (LSFO) and installing a scrubber. Partially flexible behavior only involves speed adjustments when adopting LSFO, while fully flexible behavior includes speed adjustments when adopting LSFO and installing a scrubber. Our analysis indicates that scrubber installation consistently precedes adopting LSFO in speed. Full flexibility behavior is the least costly speed adjustment behavior, while partial flexibility behavior results in the lowest emissions. The investment discrepancy on scrubbers between the carrier and the government would occur on whether or not to install a scrubber and which level of the scrubber’s quality since the two parties are concerned about the sulfur emissions and cost, respectively. Government subsidies address these discrepancies, leading to improved emission reduction.

[Translated article] Mechanical properties variations of immature bone in the earliest stages of development

IntroductionBone as a material varies its composition and mechanical properties throughout life. Although these variations are better understood in adulthood, there is little experimental information on the variation of these properties in early stages of development. The objective of this study is to analyze the mechanical behavior and chemical properties of cortical bone tissue from two animal species in these earliest stages. Material and methodologyTwenty specimens of cortical bone were manufactured from bovine and ovine species that were in different stages of development (feeding exclusively on breast milk, in the transition period to feed or pasture, and young animals but on a solid food diet). The specimens were subjected to tensile tests, recorded with a high-speed camera to obtain deformation maps. Measurements of the tensile force until the specimen broke were also carried out. A fractographic study was carried out with a scanning electron microscope to analyze the fracture surface and an analysis of the amount of calcium in each of the specimens using X-ray dispersion spectroscopy. ResultsA statistically significant and positive correlation was found between the elastic modulus of the specimens and their calcium content. A trend towards more rigid behavior with age was observed. ConclusionsYoung bone tissue tends to stiffen with age as the calcium content increases with an increase in elastic modulus.

Study of toxic metal pollution in autistic patients in Thi-Qar Governorate

Background. Autism-spectrum disorders (ASDs) are a group of chronic neurodevelopmental conditions characterized by difficulties in social interaction and communication, as well as rigid thinking and behavior. Aim of this study. This study aimed to examine the potential impact of trace metals, specifically copper, iron, and zinc, in the development of autism spectrum disease. Materials and method. A total of 100 blood samples were collected from patients diagnosed with autism, while an additional 100 samples were taken from healthy individuals serving as a control group. The individuals separated into three distinct groups: Group A (control) consisted of one hundred healthy participants aged 3-14 years. Group B consisted of one hundred patients diagnosed with autism, ranging in age from 3 to 14 years old. Results. The findings demonstrated a substantial elevation in the levels of lead (Pb), selenium (Se), cadmium (Cd), nickel (Ni), and chromium (Cr) in all groups of patients as compared to the control group. Conclusion. The present study is of the relationship between trace elements and autism. It was observed that the concentration of lead (Pb) and chromium (Cr) was significantly higher in women who did not consume folic acid compared to those who did. On the other hand, the level of nickel (Ni) was significantly lower in women who did not consume folic acid compared to those who did.

Neuropsychiatric comorbidities in tuberous sclerosis complex patients with epilepsy: results of the TAND checklist survey.

In addition to epilepsy, individuals with tuberous sclerosis complex (TSC) experience a wide range of behavioral, psychiatric, intellectual, academic, and psychosocial problems. They usually exert a large psychological burden on individuals with these illnesses. This cross-sectional study used TSC-associated neuropsychiatric disorders (TAND) checklist interviews conducted at a single medical center. The enrollment of all subjects was > 6years, and the comorbidities of neurodevelopmental disorders were assessed by clinical psychologists before enrollment. To assess the spectrum of TAND, the TAND checklist was applied as stated in the protocol, and the responses to the TAND checklist were evaluated by clinical psychologists. In the behavioral concerns of patients with TSC without epilepsy, those with epilepsy had excessive shyness, language delay, lack of eye contact, rigid behavior, inattentiveness, and restlessness. In psychiatric disorders, autism spectrum disorder and attention-deficit/hyperactivity disorder are significantly correlated with epilepsy history. Diminished academic skills, including reading, writing, and mathematics skills, are significantly associated with epilepsy history. For intellectual ability, TSC patients without epilepsy is associated normal intelligence level. Among neuropsychological skills, deficits in attention, dual tasking/multi-tasking, visuospatial tasking, and executive skills are significantly associated with epilepsy history. Epilepsy in patients with TSC contributes to comorbid neuropsychiatric disorders. In addition to epilepsy evaluation, it is crucial to evaluate the heterogeneous spectrum of neuropsychiatric disorders using a standard checklist during the annual clinical follow-up of patients with TSC.

An Approach for Modelling Accidental Eccentricity Effects in Symmetrical Frame Buildings Exhibiting Semi-Rigid Diaphragm Behavior

The accidental eccentricity effect is specified, in earthquake codes, to account for the possible uncertainties in the mass and stiffness distribution of the structural system and the effect of the torsional component of the earthquake ground motion on the building. Türkiye Building Earthquake Code (TBEC-2018) considers the additional eccentricity effect only for the cases where rigid diaphragm behavior is provided in the slabs. However, in buildings with A2 and A3 irregularities or flexible diaphragms including insufficient strength and stiffness, the in-plane deformations and stresses on diaphragms may change the behavior of buildings under earthquake loads. In this study, a practical approach to be used in the equivalent earthquake load method was proposed to apply the accidental eccentricity effect on symmetrical frame buildings with semi-rigid diaphragms. The approach is based on distributing the total accidental torsion to the nodes as fictitious forces. Two numerical examples were presented. The first is a single-story precast industrial-type RC building, where the calculation steps of the procedure explained in detail. The building was modeled with both semi-rigid and rigid diaphragm assumptions, and a comparison of two modeling assumptions under accidental torsion was presented. Torsional irregularity factors obtained from building modeled by semi-rigid diaphragm assumption provided greater values with respect to those modeled by rigid diaphragm. This shows the significance of considering accidental eccentricity for semi-rigid diaphragms. The second numerical example, which is a RC concrete building, was used to validate the proposed methodology via finite element model (FEM) built-in algorithm. The obtained displacement demands by using the proposed methodology were very close to FEM results as a reference for the real solution. It is concluded from this study that the proposed methodology is reliable and can be used for modeling accidental eccentricity effects on symmetrical-plan buildings with semi-rigid diaphragms.

Analytical rheology as a tool for the structural investigation of citrus pectin.

Rheological analysis of citrus pectin at pH 3 and 7 elucidates its structural dynamics, revealing distinct behaviors influenced by pH. At pH 3, pectin exhibits shear-thinning, with solvent-independent unified rheological profiles identifying three concentration regimes: 0.5%-1.5%, 2%-3%, and 3.5%-4%. These regimes, alongside Cox-Merz superpositions, outline the semi-dilute (c*) and concentrated (c**) transitions at 1.5%-2% and 3%-3.5%, respectively. Moreover, a Morris equation exponent of 0.65 indicates flexible, mobility-restricted macromolecules. Conversely, at pH 7, increased viscosities and Morris plot linearity for p = .1 suggest rigid chain behavior due to electrostatic repulsion among ionized acidic groups. This rigidity leads to concentration-dependent self-assembly structures that diverge from expected unified rheological profiles, a deviation amplified by heating-cooling cycles. This study clarifies the impact of pH on citrus pectin's rheology and emphasizes the intricate relationship between polymeric chain rigidity, self-assembly, and viscosity. By providing a refined understanding of these mechanisms, our findings contribute to the broader field of polysaccharide research, offering insights critical for developing and optimizing pectin-based applications in various industries.

Impact of hydrocarbon exposure on the mechanical properties of rail pads

This study investigates the effect of hydrocarbon exposure on the mechanical behaviour of seat pads used as a part of the fastening system in rail transport. Three different types of rail pads are examined, two made of EPDM (Ethylene Propylene Diene Monomer) and one made of EVA (Ethylene Vinyl Acetate). The results indicate that hydrocarbon exposure has a significant effect on the dynamic stiffness and mass stability of the pads, particularly in the EPDM ones. More specifically, it is observed that EPDM exposure to hydrocarbons increases the flexibility of the pads. Furthermore, for prolonged exposure periods (500 hours), this flexibility can become so pronounced that exhausts the pad's ability to deform under the loads applied during track assembly, which results in a more rigid behaviour than aging. Such findings are important as they suggest that hydrocarbons can negatively impact the performance and safety of rail transport due to the changes induced in critical mechanical properties of pads. Consequently, measures should be taken by contractors and infrastructure managers to reduce the adverse influence of hydrocarbons on rail pads, which contributes to increase the safety and efficiency of rail transport.