Car Truck Research Articles

Simulation of spring-friction set of freight car truck, taking into account track profile

The purpose of this article is the mathematical modeling of a spring-friction set of a freight car trolley depending on the profile of the railway track. The article uses the methodology of the results of the generalized model of power interaction of friction pairs "pressure beam-friction wedge" and "friction wedge-friction bar" of the spring-friction set of the cart 18-578 in the mechanical system "track-car-load," in a particular case cart from which such models of the e of the freight car 18-100 can be obtained. The manuscript contains a software study using a computer simulation of a freight wagon trolley, which complements the experimental studies. The mathematical (symbolic) method in the computer algebra system MathCAD (a type of computer-aided design system) is used to solve the equations of equilibrium of the supercharger beam as a real object. In the course of the experimental study, a computational mathematical model of the force action of friction pairs of spring-absorbing trolley apparatuses was developed, and the results of calculations of the reaction of the friction bar to the friction wedge were mathematically obtained. The optimal parameters were obtained analytically, and the indicators of the angles of inclination of the contact surfaces of the trolley of the freight car were justified.

Effects of Adaptive Cruise Control System on Traffic Flow and Safety Considering Various Combinations of Front Truck and Rear Passenger Car Situations

Existing studies on the heterogeneity in traffic flow have considered either conventional car–truck or conventional vehicle–automated vehicle combinations. Nevertheless, these assumptions are not realistic as there will be possible combinations of cars–trucks and conventional–automated vehicles in the future. This study aims to investigate heterogeneous traffic flow with or without an adaptive cruise control (ACC) system for the pair of a front truck and a rear passenger car. Vissim microscopic traffic simulation software and the HighD dataset were applied. The major findings include the following. (1) The greater the penetration rate of ACC vehicles in the same speed interval, the smaller the space headway of the rear car. (2) Both conventional and ACC cars accelerate or decelerate frequently when their speeds exceed that of the front truck in the car-following state. In the free-flow state, a conventional car keeps a constant speed or accelerates, while an ACC car mainly adopts an acceleration strategy. (3) The variation of speed differences and space headways is smallest when both the front truck and rear car have ACC. (4) The probability of conflicts between the front truck and rear car pair decreases with the increase of market penetration of ACC vehicles. Compared to conventional cars, the rear car equipped with ACC exhibits a lower probability of conflicts. Statistical tests further confirmed the significant differences between any two of the four combinations based on the ACC equipment.

Effects of leakage location and ventilation condition on hydrogen leakage during shipping of fuel cell vehicles

In the process of shipping hydrogen fuel cell vehicles, due to the special characteristics of the design and construction of the pure car truck carrier (PCTC) and its working environment, once hydrogen leakage occurs, it is easy to cause safety accidents, resulting in economic losses and human casualties. The current ventilation regulations are only for the shipping of vehicles with internal combustion engines and there are no clear regulations on the ventilation requirements for PCTCs during the shipping of hydrogen fuel cell vehicles. First, a PCTC and a hydrogen fuel cell vehicle were selected for the study and the corresponding geometries were modeled. For the scenario of hydrogen leakage in the cabin of the ship, the amount of hydrogen leakage is calculated according to the leakage model. Then, using Fluent software, the diffusion process of hydrogen between the two vehicles is simulated and the variation pattern of hydrogen concentration is concluded. Finally, simulations are carried out under different leakage locations and ventilation conditions to analyze the influencing factors of hydrogen diffusion distribution in the cabin of the ship. The simulation results identify the optimum location for the hydrogen sensors and provide a reference for the setting of safety measures and development of regulations on ventilation requirements when shipping hydrogen fuel cell vehicles.

Study on the Resistance of a Large Pure Car Truck Carrier with Bulbous Bow and Transom Stern

The resistance of a large Pure Car Truck Carrier (PCTC) with a bulbous bow and a transom stern is evaluated in the present paper. Several cases at nine different ship speeds in calm water are simulated and results are compared with the experimental measurements. The maximum relative error is 0.93% at a Froude number (Fr) of 0.209. The total resistance coefficient of the ship in calm water shows a parabolic trend with increasing Fr, and it reaches a minimum value at Fr = 0.1794. Furthermore, the cases of the ship in regular waves with six different wavelengths and three wave heights are simulated. It is observed that the total resistance exhibits a quadratic relationship with the wavelength when the wave height is fixed. The wave-making resistance increases with the increase in wave height at any fixed wavelength, and it reaches a maximum value when the wave-length is 1.2 times the ship length (Lpp). Additionally, we also investigated the resistance in three different sea states at four different speeds. When the significant wave height of irregular waves is the same as regular waves, the wave-making resistance under irregular waves is much smaller than that of the regular waves. All of these results indicate that the bulbous bow and transom stern can reduce the wave-making and residuary resistances, which can provide a useful reference for the subsequent design and manufacturing of related ships.

A cellular automata model for car–truck heterogeneous traffic flow considering drivers’ risky driving behaviors

Driving behavior is the core of traffic simulation modeling. Despite the sizable efforts to investigate the influence of risky driving behavior on traffic flow, very little is known about its influence under car–truck heterogeneous traffic conditions. Therefore, this study aims to analyze the influence of several common risky driving behaviors on car–truck heterogeneous traffic flow. A two-lane cellular automata (CA) model for heterogeneous traffic flow consisting of cars and trucks was proposed, the conditions for the occurrence of dangerous situations (DSs) and traffic congestion were defined. Then the vehicle performance under the influence of risky driving behaviors prevalent in car–truck heterogeneous traffic was obtained and incorporated into the proposed CA model to measure their influence on crash probabilities and congestion rates. The simulation results indicate that risky driving behaviors have a significant negative influence on traffic safety and efficiency, increasing the frequencies of DSs, reducing the traffic flow and aggravating the traffic congestion. In addition, the combinations of risky driving behaviors in traffic flow further deteriorate the traffic safety and efficiency. For example, when two risky driving behaviors, such as distracted driving and aggressive lane-changing, affect the traffic flow simultaneously, the frequencies of DSs increase dramatically and in some density ranges, they are even higher than the sum of the frequencies caused by two single risky driving behaviors. These findings may have notable practical implications in developing policies and regulations that enable truck operations without compromising safety and efficiency.

A study of the factors affecting driving risk perception using the Bivariate Ordered Probit model

This paper aims to examine the key factors influencing driving risk perception in Iran. We conducted separate surveys for two groups of Iranian drivers, namely passenger car drivers and truck drivers. In order to assess driving risk perception, respondents were asked what they think about their Probability of Having a Road Accident (PHRA) and if they eventually have an accident as a driver, what they think about the Probability of it being Fatal or causing Severe Injury (PFSI). A Bivariate Ordered Probit model, which considers the possible correlation between PHRA and PFSI, was developed to explain the observed driving risk perception using type of vehicle, driving experience, socio-demographic information, and driving behaviour. According to the results, vehicle type, vehicle age, driving experience, sleep quality, at-fault accidents over the past three years, vehicles safety-related equipment, and education level have significant effects on driving risk perception (p-value < 0.05). In addition, this paper compares the driving risk perception of truck and passenger car drivers. The results show that truck drivers have a higher perception of PHRA and PFSI compared with passenger car drivers (p-value < 0.05). The results may convince policy-makers to consider the characteristics of the two categories of drivers when designing regulations.

Analysis of Chinese Typical Lane Change Behavior in Car–Truck Heterogeneous Traffic Flow from UAV View

Chinese driver behavior in heterogeneous traffic is commonly available, but it is difficult to acquire due to view limitations and sensor limitations. In this study, Chinese typical lane change behavior in car-truck heterogeneous traffic flow was collected and analyzed using an Unmanned Aerial Vehicle (UAV). The velocity of ego vehicle, relative velocity and distance of ego and surrounding vehicles, time to collision (TTC), time headway (THW) at the lane change moment, and brake and accelerate reaction time during lane changes were investigated. Results showed that large differences existed in various car follow types and lane change types. Cars drove more aggressively than trucks with shorter reaction times, and cars would change lanes at a longer distance when facing trucks. Smaller TTC and THW were found for trucks when facing cars. Chinese drivers showed more frequent lane-change maneuvers and shorter reaction times compared to other countries. The driver characteristic in China provided data support for the training of artificial intelligence-based decision algorithms, the development of a localized system, and the design of roads.

Heterogeneous traffic flow characteristics on the highway with a climbing lane under different truck percentages: The framework of Kerner’s three-phase traffic theory

Nowadays, in order to improve the traffic conditions in mountainous areas, the demand of climbing lanes is increasing. In this paper, car–truck heterogeneous traffic flow characteristics on the highway with a climbing lane are studied up based on an improved Kerner–Klenov–Schreckenberg–Wolf (KKSW) cellular automation (CA) model. To depict the speed characteristics of vehicle’s climbing and lane-changing behaviors, additional evolution rules for trucks are introduced into the KKSW model. Specifically, the motion of trucks climbing on the slope is described as a deceleration process and an equilibrium process. Furthermore, we define the probability of a truck driver using the climbing lane as a function of the observed real-time occupancy on it. We have found that in accordance with Kerner’s theory, traffic breakdown is an F→S transition that occurs in metastable free flow with respect to the F→S transition. When the traffic demand increases, the bottleneck appears due to the merging of trucks from the climbing lane to the inner lane. Localized synchronized flow patterns (LSP) emerge on both the inner and outer lanes. When traffic demand increases further, wide moving jams emerge in synchronized flow and general pattern (GP) appears on the inner lane, whereas synchronized flow patterns remain on the outer lane only. In addition, the macroscopic traffic flow characteristics under varying truck percentages are analyzed. We have found that the improving effect of climbing lane on traffic efficiency is closely related to the truck percentage.

Modeling Car-Following Heterogeneities by Considering Leader–Follower Compositions and Driving Style Differences

To better understand the behavioral heterogeneities of human-operated vehicles, the paper proposes a method to distinguish car-following behaviors in specific leader–follower contexts. Using the Next-Generation Simulation dataset, the car-following data are first classified into four leader–follower compositions, namely, truck–car, car–car, car–truck, and truck–truck. Based on the classified data, we calibrate the parameters of a few well-known car-following models, including Full Velocity Difference model, Intelligent Driver Model, and Gazis–Herman–Rothery model. Principal component analysis and clustering analysis are then applied to the calibrated parameters to discover the behavioral patterns and to find the probabilistic distributions of the parameters for the classified car-following (CCF) models. Simulation results show that compared with the unified car-following models, the estimation errors of calibrated CCF models are reduced by 20.79% to 49.05%, which indicates that the proposed method provides a more accurate description of car-following heterogeneities. The proposed framework could help highway traffic operators better know the traffic users.

Influence of Car Retarders on the Crack Growth in Side Frames of Car Trucks

Influence of Car Retarders on the Crack Growth in Side Frames of Car Trucks

LCTC Ships Concept Design in the North Europe- Mediterranean Transport Scenario Focusing on Intact Stability Issues

In late years, the size of RoRo cargo ships has continuously increased, leading to the so-called Large Car Truck Carriers (LCTC). The design of these vessels introduced new challenges that shall be considered during the ship design since the conceptual stage, which has a very strong impact on the technical and economic performances of the vessel during all its life-cycle. In this work, the concept design of an LCTC is presented based on Multi-Attribute Decision Making (MADM). A large set of design alternatives have been generated and compared in order to find out the most promising feasible designs. The proposed approach is based on a Mathematical Design Model (MDM) capable to assess all the main technical and economic characteristics for each design. Among the others, here focus has been done on the ship stability to assure the compliance with statutory rules within the MDM. A new stability metamodel has been developed capable to define the cross curves of stability at the concept design stage. The proposed MADM methodology has been applied to North Europe-Mediterranean transport scenario highlighting the impact of main particulars describing hull geometry on the technical and economic performances of an LCTC ship.

PELATIHAN PEMASARAN ONLINE BAGI USAHA HOME INDUSTRY MINIATUR MOBIL TRUK PEKON TAMBAHREJO

Digital-based sales technology or as we often know electronic commerce has experienced a very rapid increase as is felt at this time. With very tight trade competition, Miniature Truck Car Industry collaborates with the Higher Education Institute STMIK Pringsewu, to provide training services for home industry business owners to have a digital-based sales platform with the concept of mobile commerce. This Community Service activity aims to provide an understanding of how to market digital-based food products. From this activity, members who have a home industry business can market their products quickly, precisely and safely so that customers can provide convenience to customers.

Підвищення зсувної жорсткості візка моделі 18-100 вантажного вагону

Although a large number of truck models have been put into service on the 1520 mm gage railways over the past ten years, the problem of an insufficient shear stiffness of a freight car truck still remains topical. This problem is a consequence of attempts to keep a sufficient degree of unification of new truck models with the 18-100 truck because this greatly simplifies the introduction of new trucks and allows one to make the best use of the existing maintenance and repair infrastructure. However, this also results in that new designs inherit many drawbacks of the 18-100 truck. One of its critical drawbacks is a low connectedness in a horizontal plane, which reduces the critical speed and increases truck component wear. A solution to this problem may be an auxiliary stiffening frame. This paper presents a new design of an auxiliary stiffening frame for the 18-100 truck. The design increases the truck shear stiffness, thus improving freight car dynamic performance and service life. Mathematical simulation, oscillation theory, and elasticity theory methods were used to design an auxiliary stiffening frame installable between the 18-100 truck side frames without any significant changes in the freight car basic design. The physical and mechanical properties of the auxiliary stiffening frame’s structural materials were selected. Loads on the auxiliary stiffening frame were determined and then used in the calculation of the stresses that develop therein in motion. It was found that the proposed auxiliary stiffening frame with resilient polyurethane inserts increases the truck shear stiffness by 0.5 MN/m. The proposed improved design of the 18-100 truck increases its shear stiffness, improves freight car dynamic and operational performance, and reduces truck component wear. Besides, the auxiliary stiffening frame is simple in design. Because of this, its introduction will bring considerable economic benefits.

Modeling cars and trucks in the heterogeneous traffic based on car–truck combination effect using cellular automata

An improved cellular automata model based on car–truck combination effect oriented to faithfully reproducing the characteristics of heterogeneous traffic flow is presented in this paper. The model focuses on reflecting complex car-following and lane-changing behavior of cars and trucks by incorporating the difference of physical performance and driving behavior between cars and trucks and the behavioral change caused by car–truck interaction. The update rules of cars and trucks were constructed separately based on the analysis results of NGSIM and SP survey. The impact of the truck in front was introduced into the model, which can affect the lane-changing probability, safety expectation and randomization probability. As revealed by the simulation results, the driving of vehicles in the heterogeneous traffic (i.e. car–truck, truck–car, car–car and truck–truck) is reproduced properly through the model. In addition, the model is capable of reproducing the hysteresis phenomenon and identifying three typical traffic states, namely free flow, synchronized flow and jam. Under certain conditions, trucks can help to eliminate the propagation of congestion waves. Moreover, the percentage of trucks and truck impact have a significant influence on the fundamental diagram, congestion rate, lane-changing rate and traffic stability. The findings of this study can provide a basis for further research on the heterogeneous traffic.

Розробка зварної конструкції бічної рами візка вантажного вагону підвищеної надійності

Розробка зварної конструкції бічної рами візка вантажного вагону підвищеної надійності

Analysis of Pressure and Dynamic Tests of the Blocked Wheel Pair

The paper describes a modular design of a wheelset. Three prototypes of wheelsets and track were manufactured using the π theorem. Full-scale wheelsets for a cargo car truck were also manufactured. The results compare the movement dynamics of conventional and modular wheel-sets mounted on cargo car trucks.

Вибір раціональних параметрів додаткових зв’язків у візках вантажних вагонів нового покоління

Вибір раціональних параметрів додаткових зв’язків у візках вантажних вагонів нового покоління

Optimization Supply Chain Strategy of Tire Manufacturing Using Goal Programming Method

The pressure of the supply chain to reduce cost, manage shortened order-to-delivery cycles, ensure a highly efficient logistics network to store, and distribute finish products are some of the key challenges that the tire industry faces. Besides those challenges, tire manufacturers still have to deal with raw material supply, particularly natural rubber as the unique material. The natural rubber is common for all products that produce by tire manufacturers such as commercial tires and consumer tires. This paper focuses on creating the most efficient supply chain strategy in tire manufacturing by managing all constraints, including the natural rubber supply. The aims are to find the best scenario from a natural rubber that has been processed then become the valuable products that bring gain for the company. In this paper, 11 scenarios are created to determine the combination of all products that fit with the gaining profit and calculated using Goal Programming Method to find minimum deviation between the target value and all constraints. The data source used in this research based on last three years from one of largest tire manufacturing in southeast Asia. The results show that the most effective strategy is to optimize the supply of natural rubber to produce passenger car radial tires and truck & bus radial tires. This strategy has the most significant gap between the net sales and the cost of goods sold, as well as the smallest variation of inventory and transportation costs in the baseline scenario.

Does a tow-bar increase the risk of neck injury in rear-end collisions?

IntroductionDoes a tow-bar increase the risk of neck injury in the struck car in a rear-end collision? The rear part of a modern car has collision zones that are rendered nonoperational when the car is equipped with a tow-bar. Past crash tests have shown that a car's acceleration was higher in a car equipped with a tow-bar and also that a dummy placed in a car with a tow-bar had higher peak acceleration in the lower neck area. MethodThis study aimed to investigate the association between the risk of neck injury in drivers and passengers, and the presence of a registered tow-bar on the struck car in a rear-end collision. We performed a merger of police reports, the National Hospital Discharge Registry, and the National Registry of Motor Vehicles in Denmark. We identified 9,370 drivers and passengers of whom 1,519 were diagnosed with neck injury within the first year after the collision. We found a statistically insignificant 5% decrease in the risk of neck injury in the occupants of the struck car when a tow-bar was fitted compared to when it was not fitted (hazard ratio=0.95; 95% confidence level=0.85–1.05; p=0.32). The result was controlled for gender, age, and the seat of the occupant. Several other collision and car characteristics and demographic information on the drivers and passengers were evaluated as confounders but were not statistically significant. ConclusionsThe present study may serve as valuable input for a meta-analysis on the effect of a tow-bar because negative results are necessary in order to avoid publication bias.

Fatigue design and testing of automotive stabilizer bars

Stabilisers are components of the axle suspension system of cars trucks, trains and other moving road vehicles that connect the movement of the two sides of the suspension (right and left) to keep the vehicle levelled. Stabilizers experience bending and torsion at operation. In particular, their arms experience bending while the main body mainly torsional loading. In both cases, the highly stressed area is the surface, where the maximum tensile and shear stresses are acting. High strength steels and special treatments, thermal and/or mechanical, are used for the stabilisers’ manufacturing. The present study deals with necessary input data for fatigue life assessments based on the FKM guideline [1]. In addition, fatigue tests are conducted to calculate the stress-life curves of two different manufacturing processes.