JUSTIFICATION OF TECHNIQUE FOR COMFORT AND SAFETY ANALYSIS AT PASSENGER TRANSPORTATION ON VIBRATION LOAD DECREASE OF PASSENGER CAR BODY

2021 ◽  
Vol 2021 (2) ◽  
pp. 44-50
Author(s):  
Dmitriy Antipin ◽  
Elena Lukashova ◽  
Pavel Zhirov
Keyword(s):  
Finite Element ◽  
Metal Structure ◽  
Comfort Level ◽  
Passenger Car ◽  
Body Vibration ◽  
Passenger Comfort ◽  
Vibration Load ◽  
Car Body ◽  
Passenger Transportation ◽  
The Impact

The purpose of the work is to increase comfort and safety of railway passenger transportation, at the expense of passenger car body vibration load decrease. The analysis of the investigations carried out and dedicated to the definition of rigidity property impact upon the level of passenger comfort and traffic safety has shown that the first mode of vertical bending impacts considerably upon car body dynamic behavior. The analysis of vibration load impact upon passenger car body was carried out in accordance with Dumitriu’s technique. As apposed to the investigations carried out earlier in the paper the data on car metal structure acceleration are obtained through the methods of mathematical modeling based on solid and finite element models. On the basis of the data obtained and natural running tests there was created and verified a particularized lamellar finite-element model of a car body with the aid of which there were obtained values of vertical and horizontal accelerations of a car body metal structure. The analysis of the results obtained has shown that within the frequency range of 8.9. – 20 Hz there are observed acceleration surges which are among the most sensitive ones in terms of the impact upon man and transport comfort support. At the frequencies obtained there was carried out a passenger comfort investigation with the aid of which it was defined that at the frequency of car body own bending oscillations of 8.9 Hz – a comfort index is above 4 units that shows a low comfort level. A frequency of 8.9 Hz corresponds to a vertical bending mode which is the most significant mode of car body deformation in terms of passenger comfort support. With regard to this in the works there was offered a number of efficient measures for strengthening car body structure bearing capacity with the goal of its bending rigidity increase which provides an installation of a supplementary bearing partition in the mid-section of a car body, and also the introduction of auxiliary longitudinal elements in a frame supporting design. For the effectiveness assessment of measures offered there was carried out re-investigation according to the technique described. As a result of the computation it was defined that the design measures offered allowed increasing a frequency value of own bending vibration of car body metal structure up to 11.7 Hz. The analysis of the results obtained allowed drawing a conclusion of the effectiveness of design solutions offered on car body vibration load decrease.

SIMULATION OF LOADING OF THE BODY OF A DOUBLE-STOREY PASSENGER CAR IN A FOCAL FIRE WITH SPECIFIED CHARACTERISTICS

2020 ◽  
Author(s):  
Dmitriy Antipin ◽  
Mihail Bulychev ◽  
Gennadiy Petrov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Carrying Capacity ◽  
Thermal Loading ◽  
The Body ◽  
Finite Element Scheme ◽  
Passenger Car ◽  
Element Scheme ◽  
Car Body ◽  
Element Method

A simplified method has been developed for assessing the loading of the load-bearing systems of passenger cars under thermal loading with a fire spot with limited properties. A system of simplifications for realizing a combustion spot is substantiated. A method for its implementation is proposed. The description of the object of research is given with the necessary thoroughness of presentation. A finite element scheme has been developed and adapted, taking into account the application of thermal loads in the system of an industrial software complex that implements the finite element method. Verification of the finite element scheme was carried out taking into account full-scale normative experiments. A conclusion is made about the possibility of the applicability of the finite element scheme for the study. Numerical experiments have been carried out to assess the carrying capacity of the body of a double-deck passenger car when it is exposed to a combustion center with known thermal parameters. The experiments were built and performed in a finite element method system. The results of simulations in the affected zone of the alleged fire were obtained for the conditional spot of its location. Comparison of the results with the static loading mode of the car body is considered. The analysis of the results obtained is carried out. A conclusion is given on the effect of a small localization fire on the carrying capacity of the car body. The proposed method is evaluated taking into account the possibility of further use

scholarly journals APPLICATION OF CAD FOR ANALYSIS OF STRENGTH CHARACTERISTICS OF PASSENGER CAR BODY STRUCTURES

2021 ◽  
Author(s):  
Svetlana Ashurkova
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Strength Characteristics ◽  
Cad Tools ◽  
Passenger Car ◽  
Design Models ◽  
Load Bearing ◽  
Car Body

The development of finite element design models of the passenger car body using modern CAD tools was carried out. An assessment of the strength, stability and fatigue life of the load-bearing structures of the passenger car body has been carried out.

scholarly journals Impact Test of a Crash-Energy Management Passenger Rail Car

Joint Rail ◽  
2004 ◽  
Author(s):  
Karina Jacobsen ◽  
David Tyrell ◽  
Benjamin Perlman
Keyword(s):  
Energy Management ◽  
Impact Test ◽  
Test Results ◽  
Structural Components ◽  
Passenger Car ◽  
Dynamic Component ◽  
Car Body ◽  
Passenger Rail ◽  
The Impact ◽  
Crush Zone

On December 3, 2003, a single-car impact test was conducted to assess the crashworthiness performance of a modified passenger rail car. A coach car retrofitted with a Crash Energy Management (CEM) end structure impacted a fixed barrier at approximately 35 mph. This speed is just beyond the capabilities of current equipment to protect the occupants. The test vehicle was instrumented with accelerometers, string potentiometers, and strain gages to measure the gross motions of the car body in three dimensions, the deformation of specific structural components, and the force/crush characteristic of the impacted end of the vehicle. The CEM crush zone is characterized by three structural components: a pushback coupler, a sliding sill (triggering the primary energy absorbers), and roof absorbers. These structural mechanisms guide the impact load and consequent crush through the end structure in a prescribed sequence. Pre-test activities included quasi-static and dynamic component testing, development of finite element and collision dynamics models and quasi-static strength tests of the end frame. These tests helped verify the predicted structural deformation of each component, estimate a force-crush curve for the crush zone, predict the gross motions of the car body, and determine instrumentation and test conditions for the impact test. During the test, the passenger car sustained approximately three feet of crush. In contrast to the test of the conventional passenger equipment, the crush imparted on the CEM vehicle did not intrude into the passenger compartment. However, as anticipated the car experienced higher accelerations than the conventional passenger car. Overall, the test results for the gross motions of the car are in close agreement. The measurements made from both tests show that the CEM design has improved crashworthiness performance over the conventional design. A two-car test will be performed to study the coupled interaction of CEM vehicles as well as the occupant environment. The train-to-train test results are expected to show that the crush is passed sequentially down the interfaces of the cars, consequently preserving occupant volume.

scholarly journals SUBSTANTIATION OF DESIGN SOLUTIONS FOR PASSENGER CAR BODY BEARING STRUCTURES WITH PERFORATED REINFORCING ELEMENTS

2019 ◽  
Vol 2019 (6) ◽  
pp. 69-76
Author(s):  
Светлана Ашуркова ◽  
Svetlana Ashurkova ◽  
Дмитрий Антипин ◽  
Dmitriy Antipin
Keyword(s):  
Finite Element ◽  
Model Development ◽  
Element Model ◽  
Structure Design ◽  
The Body ◽  
Passenger Car ◽  
Design Models ◽  
Car Body ◽  
Body Design ◽  
Bearing Structure

As a method of investigations there is adopted a computer mathematical modeling based on the use of a finite element method. The choice of a type and perforation parameters is connected with the problem in the large array creation of bearing structure design models of passenger car bodies. The analysis of investigations carried out in the field of multi-variation computations has shown that the most efficient investigation method is a superelement reduction. Its use allows decreasing labor and time costs for the body design model development at the expense of the initial super-element with the perforation area for a new one. The appraisal of the procedure offered on the choice of a body efficient bearing structure with the perforated profiles is carried out by the example of the body of a domestic passenger car according to the criteria of strength and assurance of the highest weight reduction of a bearing structure. In the first stage of the work there are defined types and parameters of perforation possible for use in the structure. Finite element design models of car bodies are developed. On the basis of strength computation results the reinforcing elements of the structure are offered which have a margin safety for perforation application in them. Based on the analysis of car body bearing structure there is carried out a choice of an efficient unit of a finite element model which will be used as a super-element. In the next stage of the work there are developed and computed structures of car bodies with the perforation types under consideration and with the use of superelements. The computation results have shown that maximum design stresses of car bodies for all perforation types under consideration do not exceed legitimate values. As an efficient bearing structure of a passenger car body there is adopted a car body with the sixth type of perforation ensuring the largest decrease of structure metal intensity and satisfying strength requirements. The procedure developed can be used at designing modern bearing structures of passenger car bodies having improved technical and economic values.

КОНСТРУКТИВНО-ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ХВОСТО-ВИХ БАЛОК СІТЧАСТОГО ТИПУ З ПОЛІМЕРНИХ КОМПО-ЗИЦІЙНИХ МАТЕРІАЛІВ ВЕРТОЛЬОТІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

2020 ◽  
pp. 15-30
Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Layer Structure ◽  
Metal Structure ◽  
Element Model ◽  
Stress Strain ◽  
Element Analysis ◽  
Mesh Structure ◽  
Stress Strain State ◽  
Mesh Structures

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.

scholarly journals Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change

2015 ◽  
Vol 12 (19) ◽  
pp. 5871-5883 ◽  
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield
Keyword(s):  
Climate Change ◽  
Finite Element ◽  
Structural Integrity ◽  
Geometric Model ◽  
Algal Growth ◽  
Coralline Algae ◽  
Rocky Shores ◽  
Element Analysis ◽  
Scan Data ◽  
The Impact

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.

A Fracture Mechanics Based Parametric Study of the Copper-to-Copper Direct Thermo-Compression Bonded Interface Using Finite Element Method

2013 ◽  
Author(s):  
Ah-Young Park ◽  
Satish Chaparala ◽  
Seungbae Park
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Parametric Study ◽  
Initial Crack ◽  
Bonding Interface ◽  
Interface Condition ◽  
Large Temperature ◽  
Bonded Interface ◽  
The Impact ◽  
Element Method

Through-silicon via (TSV) technology is expected to overcome the limitations of I/O density and helps in enhancing system performance of conventional flip chip packages. One of the challenges for producing reliable TSV packages is the stacking and joining of thin wafers or dies. In the case of the conventional solder interconnections, many reliability issues arise at the interface between solder and copper bump. As an alternative solution, Cu-Cu direct thermo-compression bonding (CuDB) is a possible option to enable three-dimension (3D) package integration. CuDB has several advantages over the solder based micro bump joining, such as reduction in soldering process steps, enabling higher interconnect density, enhanced thermal conductivity and decreased concerns about intermetallic compounds (IMC) formation. Critical issue of CuDB is bonding interface condition. After the bonding process, Cu-Cu direct bonding interface is obtained. However, several researchers have reported small voids at the bonded interface. These defects can act as an initial crack which may lead to eventual fracture of the interface. The fracture could happen due to the thermal expansion coefficient (CTE) mismatch between the substrate and the chip during the postbonding process, board level reflow or thermal cycling with large temperature changes. In this study, a quantitative assessment of the energy release rate has been made at the CuDB interface during temperature change finite element method (FEM). A parametric study is conducted to analyze the impact of the initial crack location and the material properties of surrounding materials. Finally, design recommendations are provided to minimize the probability of interfacial delamination in CuDB.

The prediction of vehicle vibration transmitted to the occupant using a modular transfer matrix

2021 ◽  
pp. 107754632199759
Author(s):  
Jianchun Yao ◽  
Mohammad Fard ◽  
John L Davy ◽  
Kazuhito Kato
Keyword(s):  
Finite Element ◽  
Transfer Matrix ◽  
Dynamic Performance ◽  
Complex Structure ◽  
Vehicle Body ◽  
Computational Time ◽  
Accurate Estimation ◽  
Finite Element Models ◽  
Transfer Matrices ◽  
Body Vibration

Industry is moving towards more data-oriented design and analyses to solve complex analytical problems. Solving complex and large finite element models is still challenging and requires high computational time and resources. Here, a modular method is presented to predict the transmission of vehicle body vibration to the occupants’ body by combining the numerical transfer matrices of the subsystems. The transfer matrices of the subsystems are presented in the form of data which is sourced from either physical tests or finite element models. The structural dynamics of the vehicle body is represented using a transfer matrix at each of the seat mounting points in three triaxial (X–Y–Z) orientations. The proposed method provides an accurate estimation of the transmission of the vehicle body vibration to the seat frame and the seated occupant. This method allows the combination of conventional finite element analytical model data and the experimental data of subsystems to accurately predict the dynamic performance of the complex structure. The numerical transfer matrices can also be the subject of machine learning for various applications such as for the prediction of the vibration discomfort of the occupant with different seat and foam designs and with different physical characteristics of the occupant body.

scholarly journals The impact of drilling and slitting construction on damage field: evolution characteristics in low-permeability coal seam

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng
Keyword(s):  
Finite Element ◽  
Rock Mass ◽  
Damage Mechanics ◽  
Effective Strain ◽  
Secondary Development ◽  
Distribution Area ◽  
Finite Element Program ◽  
Element Program ◽  
Mining Face ◽  
The Impact

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.

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