Browse Topic: Body-on-frame

Items (41)
A variety of structures resonate when they are excited by external forces at, or near, their natural frequencies. This can lead to high deformation which may cause damage to the integrity of the structure. There have been many applications of external devices to dampen the effects of this excitation, such as tuned mass dampers or both semi-active and active dampers, which have been implemented in buildings, bridges, and other large structures. One of the active cancellation methods uses centrifugal forces generated by the rotation of an unbalanced mass. These forces help to counter the external excitation force coming into the structure. This research focuses on active force cancellation using centrifugal forces (CFG) due to mass imbalance and provides a virtual solution to simulate and predict the forces required to cancel external excitation to an automotive structure. This research tries to address the challenges to miniaturize the CFG model for a body-on-frame truck. The virtual
Paul, AbhishekLatcha, Michael
In automotive world role of suspension system is to absorb vibrations from the road, and to provide stability while vehicle is going over bumps or uneven roads, cornering, acceleration and braking etc. For body on frame SUVs which are typically characterized by high center of gravity, it is quite critical to find best balance in ensuring stability of the vehicle and having comfortable ride performance. Rigid axle rear suspension is quite a typical choice in such vehicles, wherein lower and upper control links are two important components subjected to lateral, longitudinal, and vertical loads. These links allow the vehicle to move smoothly throughout the entire range of suspension travel. Kinematics and compliance optimization of these links is a major factor in definition of ride-handling performance of the vehicle. The present study describes key challenges and methodology to define position as well as orientation of control links, where-in multiple inter-related handling and comfort
Hussain, InzamamJani, HarshilRasal, ShraddheshAsthana, ShivamAhire, ManojJadhav, PrashantLenka, VisweswaraVellandi, Vikraman
Truck maneuverability is one of the phenomena, which is considered in development stage of a commercial vehicle chassis structure. Torsional stiffness is one of the important properties of the chassis structure that significantly affects vehicle dynamic characteristics such as handling and rollover. The torsional stiffness is preferred to be as high as possible since lower torsional stiffness may cause resonance, vibration, poor handling, and rollover. Torsional stiffness can be improved through minor modification in the conventional ladder chassis frame. This paper presents the comparative study on improving the torsional stiffness of the chassis frame. The objective is to achieve the improved torsional stiffness by varying the neutral axis of the frame long member section at a desirable region. Torsional stiffness is dependent of the sectional modulus; this study provides an insight on increasing the torsional stiffness without addition of section modulus
Gowtham, G.V.N.Baashkaran, M.K.Naveen, Sukumar N.
In most farm tractors through the middle of the 20th century, a pressed steel frame chassis is used as a supporting part of the tractor on which the engine, wheels, axle assemblies, transmission, steering mechanism, brakes, and suspension members were mounted together. Farm tractors generally used in the agricultural field experiences a variation in the load and vibrations, which leads to failure/fracture in the frame/chassis. In order to reduce the failure/fractures in the chassis/frame, high strength materials are used. Therefore, the main objective of the paper is to identify the best suitable high strength material and most suitable cross section for a mini tractor chassis, so as to make it very strong to bear the heavy loads and shocks received while working in the farms in static conditions. In the present work, ladder chassis is designed and analyzed with three different types of cross sections like C, I and Rectangular box type. Considering the maximum load condition, analysis
Aruchamy, SathishkumarRanganathan, SoundararajanChithrambikai, Dharini ArumugamBABU, SANTHOSH
Accurate prediction of in-vehicle powertrain bounce mode is necessary to ensure optimum responses are achieved at driver’s touch points during 4post shake or rough road shake events. But, during the early stages of vehicle development, building a detailed vehicle finite element (FE) model is not possible and often powertrain bounce modes are computed assuming the powertrain to be a stand-alone unit. Studies conducted on FE models of a large SUV with body on frame architecture showed that the stand-alone approach overestimates the powertrain bounce mode. Consequently, there is a need for a simplified version of vehicle model which can be built early on to compute powertrain modes. Previously, representing all the major components as rigid entities, simplified unibody vehicle models have been built to compute powertrain modes. But such an approach would be inaccurate here, for a vehicle with body on frame architecture due to the flexible nature of the frame (even at low frequencies). To
Maddali, RamakanthMogal, Akbar BaigHaider, Syed
This paper investigates the application of torque weighting to vibration dose value. This is done as a means to enhance correlation of perceived drive comfort directly to driver pedal commands while rejecting uncorrelated inputs. Current industry standards for vehicle comfort are formulated and described by ISO2631, which is a culmination of research with single or multi-axis vibration of narrow or broadband excitation. The standard is capable of estimating passenger comfort to vibrations, however, it only accounts for reaction vibrations to controlled inputs and not perceived vibration request vs. response vibration. Metrics that account for torque inputs and the vibration response create actionable estimates of dosage due to driver torque requests without uncorrelated inputs. This reduces the need for additional accelerometers and special compensating algorithms when road or track testing. The use case for the proposed modified metric is during the powertrain calibration process
Furlich, JonRobinette, DarrellBlough, Jason
During development of new vehicles, CAE driven optimizations are helpful in achieving the optimal designs. In the early phase of vehicle development there is an opportunity to explore shape changes, gage reduction or alternative materials as enablers to reduce weight. However, in later phases of vehicle development the window of opportunity closes on most of the enablers discussed above. The paper discusses a simplified methodology for reducing the weight in design cycle for truck frames using parametric Design of Experiments (DOE). In body-on-frame vehicles, reducing the weight of the frame in the design cycle without down gaging involves introducing lightening holes or cutouts while still maintaining the fatigue life. It is also known that the lightening holes might cause stress risers and be detrimental to the fatigue life of the component. Thus the ability to identify cutout locations while maintaining the durability performance becomes very critical. This paper describes a method
bhat, RamachandraSharma, NitinRivard, CliffordThomson, Kevin
Paper withdrawn by author
Roy, NantuScheiblegger, ChristianDarling, JosPfeffer, Peter E.
Although its best-ever sales year was barely more than 50,000 units and many critics questioned the buying public's desire for a midsize pickup based on a unibody structure instead of the tried-and-true body-on-chassis layout, Honda remained faithful to the concept it introduced with the first-generation Ridgeline pickup, producing it for ten years from 2005-2014. Even through the recession and auto-industry downturn, Honda insisted it was keen to develop a second-generation Ridgeline, to continue to press the idea that if many in pickup-crazed America took an honest look at what they want from a pickup-and equally important, how they actually use a pickup-a unibody-based design would be the most satisfying choice
Visnic, Bill
Traditional accident reconstruction analysis methodologies include the study of the crush-energy relationship of vehicles. By analyzing the measured crush from a vehicle involved in a real world accident and comparing it to a test vehicle with a known energy, from a crash test, the real world vehicle's damage energy can be evaluated. In addition, the change-in-velocity (Delta-V) can be calculated. The largest source of publicly available crash tests is from the National Highway Traffic Safety Administration (NHTSA). NHTSA conducts numerous Federal Motor Vehicle Safety Standard (FMVSS) compliance and New Car Assessment Program (NCAP) testing for many passenger vehicles for sale in the United States. The NHTSA crash test data is available for analysis, but the data set is limited to production vehicles that are manufactured in significant quantities and it contains virtually no data relating to medium-to-heavy duty vehicles To date, there are no publically available controlled, full
Steiner, John C.Olsen, JohnWalli, TomKress, TylerArmstrong, ChristopherGallagher, RalphHusher, SteinKyes, John
This paper investigates the crashworthiness of structural composite components in frontal and side crash tests. In addition, the safety benefits of composites applications in future lighter vehicles are studied. The methodology of the research includes two steps: (1) developing a light-weight vehicle based on a current finite element (FE) vehicle using advanced plastics and composites, and (2) evaluating the crashworthiness of the light-weighted vehicle by frontal and side New Car Assessment Program (NCAP) test simulations. An FE model of a 2007 Chevrolet Silverado, which is a body-on-frame pickup truck, was selected as the baseline vehicle for light-weighting. By light-weighting components in the Silverado, the vehicle weight was reduced 19%. As a result, the content of plastics and composite in the light-weighted vehicle was 23.6% of the total weight of the light-weight vehicle. Light-weighted composite structural components include bumpers, front-end module, fenders, pillar
Park, Chung-KyuKan, Cing-Dao (Steve)Hollowell, William Thomas
Filled-rubber is widely used in automotive applications for noise and vibration isolation. The inherent material characteristics of filled-rubber make it suitable for these applications, but its complicated nonlinear behavior under both static and dynamic loading can make material modeling a challenge. This paper presents a two-element overlay technique to capture the nonlinear vibration amplitude dependency of a carbon-filled rubber material commonly referred to as the “Payne Effect.” This overlay technique is practically applied to predict the nonlinear dynamic stiffness and damping loss characteristics of a carbon-filled rubber body cab mount component from a body-on-frame vehicle calculated as a function of large static pre-strain, dynamic excitation frequency, and small dynamic strain amplitude in a single analysis. The first layer of elements is assigned a joint hyperelastic and linear viscoelastic material model that captures the pre-strain and frequency dependent behavior of
Hartley, Christopher RobertChoi, Jaehwan
Among the key parameters that decide the success of a vehicle in today's competitive market are quietness of passenger cabin (in respect of both airborne and structure-borne noise) and low levels of disturbing vibration felt by the occupants. To control these values in body-on-frame construction vehicles, it is necessary to identify major transfer paths and optimize the isolation characteristics of the elastomeric mounts placed at several locations between a frame and the enclosed passenger cabin of the vehicle. These body mounts play a dominant role in controlling the structure-borne noise and vibrations at floor and seat rails resulting from engine and driveline excitations, and they are also a vital element in the vehicle ride comfort tuning across a wide frequency range. In the work described in this paper, transfer path tracking was used to identify root cause for the higher noise and vibration levels of a diesel-powered sports utility vehicle. It was found that the one of the
Kalsule, DhanajiHudson, DavidYeola, YogeshBohari, Jakir
In this paper, a methodology is discussed to achieve cost-effective solutions for improving vehicle Noise, Vibration and Harshness (NVH) performance of a body-on-frame Multi-Utility Vehicle (MUV). The subject vehicle had objectionable levels of in-cab boom and gear rattle while accelerating in higher gears due to power-train and driveline excitations. Potential transfer paths which might be responsible for amplifying these phenomena were tracked using contemporary noise and vibration measurement techniques. Various modifications were evaluated to improve NVH performance under constraints of vehicle-packaging. An optimized combination of these modifications resulted in improvements in the NVH performance over a wide range of operating speeds with reductions of up to 10 dB achieved in firing frequency excitation, thus eliminating the objectionable boom and gear rattle from the vehicle
Kalsule, Dhanaji J.Vikram, M. R.Ambardekar, M. NHudson, David
The new 2005 Pathfinder is built on a more rugged body-on-frame platform and features a more powerful V6 and three-row seating. When it was first introduced in 1986, the Pathfinder was the lone SUV in Nissan showrooms in North America. Today the company has SUVs in many shapes and sizes including the full-size truck-based Armada and compact Xterra as well as the car-based Murano. This model variety has allowed the third-generation Pathfinder to return to its body-on-frame truck-based roots from the second-generation's unibody construction. The new model, which went on sale last month, will compete with the likes of middle SUV segment contenders such as the Toyota 4Runner, Ford Explorer, Chevrolet TrailBlazer and GMC Envoy, Dodge Durango, and Jeep Grand Cherokee. Four- and rear-wheel drive will be offered, with Nissan expecting that 70% of customers will opt for the former. The company also projects the take-rate on the four trim levels to be 15% XE (value), 30% SE (value/popularly
jost, kevin
This paper reports a study of the impact dynamic characteristics of body mounts in a body-on-frame vehicle. Two methods of dynamic analyses are utilized. One method is direct impact; and the other excitation on the body mount. Using a series of component test data, the direct impact method yields the natural frequency, f, and damping factor, ζ, for a spring-mass-damper model of a body mount. The functional relationship between the g-force versus deflection curve and f, ζ, and v (impact speed) is examined. Given a frame impulse, the excitation method predicts the body response by the convolution integral. The transient transmissibility (TT), the ability of a body mount to transmit shock impulse from the frame to the body in the early part of crash duration, is investigated. The degree of front-loadedness on the body pulse is determined by TT and thus it affects the occupant/vehicle crash response
Huang, Matthew
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