The paper investigates into the vibrational characteristics of the truck Chassis including the natural frequencies and mode shapes. Truck Chassis forms the structural backbone of a commercial vehicle. When the truck travels along the road, the truck Chassis is excited by dynamic forces caused by the road roughness, engine, transmission and more. Modal analysis using Finite Element Method (FEM) can be used to determine natural frequencies and mode shapes. In this study, the modal analysis has been accomplished by the commercial finite element packaged ANSYS. The model has been simulated with appropriate accuracy and with considering the effect of bolted and riveted joints. The Chassis has been altered by some companies for using in municipal service (street sweepers) and it raises the question: Are natural frequencies of the modified Chassis in suitable range? After constructing finite element model of Chassis and appropriate meshing with shell elements, model has been analyzed and first 6 frequencies that play important role in dynamic behavior of Chassis, have been expanded. In addition, the relationship between natural frequencies and engine operating speed has been explained. The results show that the road excitation is the main disturbance to the truck Chassis as the Chassis natural frequencies lie within the road excitation frequency range. Finally advantages of the modified Chassis which leads to the increase of the natural frequencies and placing them in the appropriate range, has been discussed.

Measuring tractor performance parameters is crucial for validating manufacturer claims and selecting a suitable tractor. Field studies often face high costs and inaccuracies due to external factors and limited parameter measurement. A Chassis dynamometer serves as an effective simulator for tractor movement on the ground. This research focused on designing and constructing an in-situ test system (Chassis dynamometer) with practical features for measuring parameters at various speeds, loads, and conditions. An accurate data acquisition system records unlimited data based on relations between drawbar traction, speed, vertical load on driving wheels, and the distance to the center of gravity. To evaluate the system, the traction performance of an MF285 tractor was tested at different load and speed levels. The drawbar pull and dynamic axle load of the 2WD tractor were measured, with a maximum traction of about 11 kN. This study successfully designed and implemented an in-situ test system to assess the traction and balance capacities of conventional tractors by applying maximum load on the driving wheels.

Due to the importance of vehicle weight reduction which can reduce fuel consumption and air pollution, changes are made in vehicles. In heavy trucks with payload limitations, a lighter trailer can provide higher load-carrying capacity and more economical benefits. Composite materials are a good candidate for material exchange due to their resistance to various conditions and low weight compared to steel. In this paper, the trailer material made of steel will be replaced by composite so that strength density will remain the same. For this purpose, the finite element method is used for static and dynamic analyses. At first, the model of a two-axle trailer is developed using SolidWorks software. Then, using standard loading and failure theories (Tsai-Hill, Tsai-Wu), the number of composite layers and their suitable angles are selected for the Chassis. Finally, the loaded trailer's static, modal, and dynamic analysis are performed using the finite element method with a composite material. Results show that 17 layers of polymer composite with glass fibers with 0-0 angle can reduce 17.7 percent weight.

Flavonoids are phenolic carbon compounds, a class of plant secondary metabolites known for their unique properties such as antioxidant, antiinflammatory, coloring agent, and many more. Due to their diverse properties, they are being utilized in the industrial sector at a very high pace. The conventional methods are limited to low amounts of biomass from the source. Synthetic biology offers a promising approach for enhancing the bioproduction of flavonoids due to its tremendous advantages over conventional extraction methods. This review focuses on recent developments in applying synthetic biology techniques specifically towards microbial synthesis of flavonoids. It provides a comprehensive overview of the recent advancements in synthetic biology approaches to optimize microbial systems for efficient flavonoid production. Emphasizing genetic engineering, metabolic engineering, and systematic design principles, these techniques represent an immense shift in bioproduction strategies. The insights presented contribute significantly to our understanding of the effectiveness of these methodologies in the production of flavonoids.

Interests of increasing the speed of high speed trains, brought more wryness about probable accidents. Whereas passenger wagon carbody is considered as a safe compartment for passengers, therefore, great attention should be paid on its design. In this study, a passenger carbody (made by Eastern Germany) and its Chassis are modeled to simulate crash analysis according to EN 15227 standard. Then, obtained results are used in order to optimize the wagon Chassis. This investigation is performed in two steps. In the first step, which consists of simulation of the original wagon model, it is found that due to the lack of efficiency in crash force absorbent, some modifications are needed to consider. In the second step, the original Chassis is modified according to modern ones and by implementing honeycomb cores as energy absorbing device, higher absorbed energy is yielded. Also, impact stresses in mid-section of the Chassis considerably decreased. The proposed energy absorbing device can be implemented in front end of the Chassis to provide a crashworthy structure, however, other investigations such as modal analysis and strength determination should be conducted precede the final structure.

This work offers a new Chassis design, namely the wheel-track, represents a mathematical model of this Chassis, and also proves the advantage of the proposed design when driving the vehicle on arbitrary terrain-rough off-road. The proposed approach can find application in the design of unmanned research mechanisms for other planets (Mars Rovers, Lunar Rovers etc. ), also for design of robots and transport of rescuers at liquidation of consequences of natural or technological disasters. The article presents the analysis of the requirements for the Chassis of extraterrestrial research unmanned mechanism demonstrated high compliance of the proposed approach. The analysis of the requirements for the Chassis of extraterrestrial research unmanned mechanism demonstrated high compliance of the proposed approach. We proposed and investigated a mathematical model of wheel-track, demonstrated the optimization of the proposed mathematical model to machine computing, demonstrated the flexibility and scalability of the mathematical model. The proposed design is an attempt to combine the advantages of a walking and wheel types of travel in one mechanism.