Relative Vertical Displacement Research Articles

Motion of a submerged body under a free surface and an ice cover in finite water depth conditions

In this study, we consider the motion of a submerged body near the free surface of a liquid and a liquid covered with an ice cover in finite water depth conditions. The influence of water depth on the nature of motion of a submerged body has been experimentally and theoretically analysed. The experiments were performed in an ice tank. The use of a cable towing system allowed the researchers to measure the magnitude of the relative vertical displacement of the submerged body resulting from the action of the lift force. The influence of ice cover on the relationship between the vertical displacement, trim angle, criterion for ice breaking, and speed of movement of the submerged body model was established. For theoretical research, the ice cover was modelled by a viscoelastic floating plate, and the submarine was modelled by a source–sinks system in a fluid flow. The influence of water depth, the presence of an ice cover, changes in the submergence depth, and the speed of movement of the submerged body on the wave resistance, lift force, and trimming moment were analysed. Theoretical results are supported by experimental data.

Frictional mid‐spliced shear links for eccentrically braced frames

AbstractAccording to the AISC Seismic Provisions for Structural Steel Buildings (AISC341‐16) and EC8, the inelastic rotation demand at the design story drift is limited to 0.08 rad for I‐shape shear links in eccentrically braced frames (EBFs). Numerical studies on EBF archetypes show that the single‐sided inelastic rotation demands can be much higher than the limiting value. In addition, these links can fail due to low‐cycle fatigue (LCF) which depends on the loading history. A mid‐spliced end‐plated detachable replaceable link has recently been developed to promote easy replacement of end‐plated links. In this paper, a frictional mid‐spliced shear link is developed to increase the inelastic link rotation capacity and LCF life of shear links. The proposed link utilizes a splice connection at the mid‐length, where frictional faying surfaces are introduced to dissipate energy. Slip at the mid‐splice connection causes a relative vertical displacement between the link ends which eventually reduces the rotation demands on the I‐shape members. Experimental and numerical studies were conducted to study the proposed link concept. Three conventional and eight frictional mid‐spliced links were tested using a nearly full‐scale test setup. The results showed that the proposed links have a pinched link shear versus link rotation response. The links were able to sustain a link rotation demand of 0.23 rad together with a significant increase in their LCF life. Numerical studies were conducted to investigate the link rotation, interstory drift, and residual interstory drift of EBF archetypes equipped with the proposed frictional link.

Nonlinear modelling for structural damage assessments of reinforced and coated longitudinally coupled slab tracks

Interface debonding and slab end arching of the anchor-reinforced and coated longitudinally continuous slab tracks have been unprecedentedly investigated in this study. A novel finite element model of the longitudinally continuous slab track has been established by incorporating a tailored cohesive zone model to mimic nonlinear constitutive relationships. The new model has been validated by over 100 field measurement data. This paper is the first to assess the influences of the dual applications of anchors and coatings on the damages of the longitudinally continuous slab tracks, and to identify the effectiveness of different track maintenance methods in mitigating track damages. This study exhibits new findings: (1) In comparison with traditional tracks, the tracks constructed with anchors, coatings, and the combined use of both can reduce the maximum vertical relative displacement between the concrete slab and the mortar layer by 75%, 40%, and 85% respectively. (2) In comparison with 4 anchors, 6 or more anchors in each slab can help to prevent inner interface defects. However, an increase in anchor quantity above 6 anchors does not have a significant impact on the interface damage mitigation. (3) For the anchor-reinforced tracks, the organic coating outweighs the inorganic coating to improve interface damage mitigation.

Performance-based blast-resistant design of RC bridge piers under vehicular bombs

Bridge piers are the critical components to support the superstructures and the blast resistance of piers has attracted extensive attention considering the ever growing deliberate and accidental explosion attacks on bridge structures. However, most of the existing studies focus on the blast-induced dynamic response of a single pier without considering the bridge redundancy, even less the actual traffic performance of the entire bridge. This paper aims to propose a performance-based blast-resistant design approach of RC bridge piers under explosions of vehicular bombs. Firstly, the distribution model of blast impulse on bridge piers is proposed with considering both the ground reflections and diffractions of piers based on the validated finite element analysis (FEA) approach. Then, the fiber beam element-based model and the above blast impulse distribution model were validated based on the dynamic monotonic loading test and the explosion test on RC frame column. Furthermore, the simplified fiber element beam-based prototype RC bridge was established and the parametric studies were performed. Finally, the response surface methodology was adopted and the performance-based blast-resistant design procedure for three design basis threats specified in FEMA, i.e., cargo van bomb, small moving van bomb, moving van bomb, was proposed with utilizing the relative vertical displacement of the mid-bent as the performance index. It derives that, (i) the proposed distribution model of blast impulse is applicable to explosions at scaled distances of 0.5–2.1 m/kg1/3; (ii) the fiber beam element-based model can well describe the global response of the blast-exploded columns/piers; (iii) the proposed performance-based blast-resistant design approach can provide an efficient tool for bridge engineers.

Thermal Simulation of Ventilated Brake Disc Based on Complex Multifield Coupled Method

In this article, considering the coupled interaction of heat, stress, material wear, and wheel–rail force transmission in the disc-braking process, a complex multifield coupled method was proposed to study thermal mechanical properties and contact state of brake discs. First, a coupled dynamic model of train, track, and brake gear was established to analyze the force transmission between brake friction pairs and wheel–rail system. Based on the coupled dynamics simulation results, a thermomechanical wear coupled model of the friction pair was established. It is found that the track irregularity results in vertical relative displacements with a range of (–2.6 mm, 2.8 mm) and makes the maximum brake force increase to 24.1 kN. As a comparison, brake bench tests without wheel–rail interaction were carried out. This showed that there was no vertical relative displacement between the friction pair, and the braking force had a stable value of 22.5 kN. The simulation results of the brake disc temperature distribution, and the friction pair contact state are consistent with the bench test results. In addition, different thermal simulation methods of the brake disc were used to verify the validity of the complex multifield coupled simulation results.

Glacial isostatic adjustment in the northern adriatic region: estimates of the contribution from the Alpine ice sheet

SUMMARY The present-day sea-level variations and vertical movements in the northern Adriatic Sea and in the highly vulnerable Venetian Lagoon result from a number of simultaneously operating contributions. These include Glacial Isostatic Adjustment (GIA), the global, long-term process arising from interactions between the cryosphere, the solid Earth and the oceans in response to the melting of continental ice sheets. Although the GIA contribution in northern Adriatic Sea has been the subject of various investigations so far, significant uncertainties still exist, especially related to the extent and chronology of the Würm Alpine ice sheet and to the rheological profile of the mantle. Here, taking advantage of the recent publication of updated deglaciation chronologies for the far field late-Pleistocene ice sheets and for the near-field alpine ice complex, we produce up-to-date estimates of the present-day rates of GIA-induced relative sea-level variations and vertical displacements in the Venetian Lagoon and in the northern Adriatic Sea, which are compared with GNSS and tide-gauge observations. From high-resolution numerical simulations, we find that GIA is responsible for a complex pattern of geodetic signals across the Po plain and the northern Adriatic Sea. The modeled GIA rates are of the order of fractions of mm yr−1, generally small – but not negligible – compared to the signals observed at local tide gauges and at GNSS sites in the Po plain and facing the Venetian Lagoon. Our results indicate that, while GIA represents a relatively small component among those responsible for present-day land movements and relative sea-level variations in the northern Adriatic Sea, its contribution needs to be taken into account for a correct interpretation of the observed geodetic variations.

Using expanded polystyrene geofoam and tire-derived aggregate in different forms to reduce vertical earth pressure on high-filled cut-and-cover tunnels

Using expanded polystyrene geofoam and tire-derived aggregate in different forms to reduce vertical earth pressure on high-filled cut-and-cover tunnelsAll authorsShamil Ahmed Flamarz Arkawazi & Mohammad Hajiazizi https://doi.org/10.1080/23311916.2022.2138100Published online:27 October 2022Display full sizeUsing the high-filled cut-and-cover tunnels (HFCCTs) provides a typical solution for the possibility of using valuable lands with plateaus terrain. Because of the high quantities of backfill soil above the HFCCT, at present, the existing estimating methods of the vertical earth pressure (VEP) may not suit the HFCCTs construction. The ability to estimate the load or pressure on the HFCCTs is essential. As a principle, the soil column pressure equation can be used to estimate VEP on the HFCCTs. This study presents a numerical investigation of the effect of using expanded polystyrene (EPS) and tire-derived aggregate (TDA) in different forms on the relative vertical displacements and VEP reduction on the HFCCTs. The results showed a significant VEP reduction on the HFCCTs, especially with the use of TDA in different forms. Also, a comparison is made between the calculated and estimated VEP values on the top of the HFCCT study model with the base conditions using the soil column pressure equation, Li et al. (2019) modified equation, and Abaqus CAE 2019 software. The calculated and estimated VEP values on the top of the HFCCT study model with the base conditions showed that the calculated value using Li et al.’s (2019) modified equation is 27.942% lower than the calculated value using the soil column pressure equation, which is a high percentage of difference. While the estimated value using Abaqus CAE 2019 is 0.156% higher than the calculated value using the soil column pressure equation, which is a low percentage of difference.

Bell-and-spigot joints mechanical properties study of PCCP under the uneven settlement of foundation: Simulation and full-scale test

Prestressed concrete cylinder pipe (PCCP) makes full use of the compressive and corrosion resistance of concrete and mortar, as well as the tensile and sealing properties of steel, and has good mechanical properties. But the bell-spigot joints are the weak points of the PCCP pipeline and are easy to be damaged. In this study, a fined 3-D FEM model of PCCP is established. Based on the calculation model of fluid–solid coupling, the stress responses of joints are analyzed when uneven settlement occurs in the foundation. The cases of the different interfaces between the two foundation soils are considered. Then, a full-scale test is carried out, and the FEM model is evaluated. The results show that visible crack will occur in the concrete when the vertical relative displacement is 83 mm, 76 mm, and 83 mm under case 1, case 2, and case 3, respectively. And the concrete damage of J3 occurs first at the root of the crown. Along the hoop direction, the damage extends from the crown to both sides, and along the axial direction, the damage extends from the root of the spigot to both sides. And there is a minimum difference of 0.11 % and a maximum difference of 26.59 % between the test and FEM results.

Effect of fender system on the dynamic response of onsite installation of floating offshore wind turbines

This paper discusses a new installation method for floating offshore wind with installation procedure, essential variables, and fender system effects on the dynamic responses. The conventional installation method involves mating wind turbines and substructures in calm and protected waters and towing the assembled units to an operating site. Due to geographical, time, and economic disadvantages, this method may be challenging to meet the rapidly surging demand for floating wind power worldwide. The new onsite installation method was introduced as an alternative, using a catamaran to install fully assembled wind turbines at the operation site. The proposed concept can be employed to install and maintain fixed and floating offshore wind turbines in any location. While the conventional installation method consists of a series of installation processes, the proposed installation steps can be performed in parallel, suggesting more flexible operation planning. Fenders and wires were applied as a mechanical coupling system to enable onsite installation in harsh offshore environments. The fender system with pretensions on wires showed reduction effects on the relative horizontal displacement, relative vertical displacement, and relative alignment by approximately 78%, 64%, and 32%, respectively. Therefore, the fender system application can significantly increase the practicality of the onsite installation method.

Shear behavior of steel keyed joints in precast concrete segmental bridges under direct shear loading

AbstractEight groups of “Z” joint specimens were designed for conducting direct shear tests on steel keyed joints. The shape, size, number and joint type of steel keys were taken as experimental parameters, and the cracking load, ultimate load, residual load, and the relationship between vertical loading force and vertical relative displacement of specimens were investigated. The results reveal that the joints relied on the mechanical occlusion between the steel keys and concrete to transmit the shear forces, the load–displacement curve of the joints had a long development course, and the joints could bear large relative displacement. The bearing capacity of steel shear keyed joints increased with the increase in diameter and material strength of the tenon. The ultimate bearing capacity of the epoxied joints with 1 and 2 steel keys were respectively 151.39%, and 69.68% higher than dry joints. Meanwhile, the epoxied joints were found to become brittle and fail in more sudden manner. After direct shear failure, the shear resistance of epoxied joints was completely provided by the steel shear key. The elastic stiffness and bearing capacity of the epoxied joints was not controlled by the number of the steel shear keys, while the dry joints were sensitive with the number of keys. By adding 1 or 2 steel shear keys to a flat joint, the ultimate bearing capacity could be increased by 3.81 and 6.06 times for dry joints, and 43% and 33% for epoxied joints, respectively.

Effect of pretension on the performance of cable bolts and its optimisation in underground coal mines with various geological conditions

Pretension is the pre-added axial tensile force on fully grouted bolt systems, which include rock bolts and cable bolts. Although a series of studies via lab testing and analytical modelling proved the importance of pretension in cable bolts, there is no systematic analysis to guide the optimal pretension values to be applied on cable bolts in different engineering geological conditions. Complicated geological conditions, such as anisotropic in-situ stress, bedding plane detachment and country rock deformation, cannot be fully represented in the lab or analytical work. In addition, field scale numerical models to investigate cable bolt performance and its interaction with various geological conditions are rare. This paper analyses the effect of pretension on the performance of cable bolts in underground coal mines via field scale numerical models, with considering different geological conditions (in-situ stress, bedding plane stiffness and rock mass properties). Numerical models were developed based on a case study mine in Australia with challenging ground conditions. The in-situ stress, properties of claystone and bedding planes are considered critical variables to be analysed. The results show higher pretension contributes to higher force along the cable bolt. Neutral points, where shear force in grout materials is zero, are used to describe the pretension-induced stress redistribution on cable bolts. Pretension also has a positive effect on roof and bedding plane management, resulting in a more stable roof condition. In addition, high pretension and high in-situ stress are more likely to result in cable-grout (CG) interface failure since the relative vertical displacement difference between cable bolts and the surrounding rock mass is higher. Once CG interface failure is generated, the pretension effect turns out to be negative, leading to severe roof sagging and bedding plane aperture. This paper provides a guide to the application of pretension in coal mining.

Experimental and numerical modeling of a piezoelectric floating system for wave energy harvesting

In this paper, a floating wave energy converter (WEC) employing a piezoelectric power take-off (PTO) for off-grid powering of electronic devices at sea is presented and its electro-mechanical behavior is investigated both experimentally and numerically. The prototype floating structure consists of two box-shaped bodies joined by flexible beam elements. Due to the wave excitation, the floaters experience relative pitch rotations and vertical displacements, which dynamically deform the piezoelectric linking element, producing a superficial charge distribution. A small-scale prototype, built in an innovative way with LEGO™ bricks, is tested under regular wave excitation in a small basin. The recorded relative motion between the floaters is used as input to calculate via multiphysics software the voltage and power output of a piezoelectric device having the same flexibility of the passive element employed in the experiments. As a starting point for more accurate simulations, a 4-dof reduced-order model (ROM) of the floating system, including a simplified piezoelectric model, is developed and the wave induced response is compared with the experimental data. The elastic connection is represented through a torsional spring and potential linear theory is employed to calculate the hydrodynamic loads. Thus, Cummins equations for the floating system are formulated in pure differential form by introducing additional equations for radiation forces. This numerical approach allows for performing in an efficient and robust way the computation of the specific response amplitude operators, characterizing the WEC’s electro-mechanical response. Introducing system modes, the electro-mechanical equations can be further simplified and, by means of their frequency-domain analytical solution, facilitate a sensitivity analysis of the system response, capture-width ratio and power output with respect to relevant parameters, highlighting optimal conditions and performance enhancements by using arrays of piezoelectric elements, both in ideal (regular waves) and realistic (irregular sea) conditions.

Mutual influence of long-span urban highway tunnel and rail transit construction

In order to analyze the mutual influence between the long-span highway tunnel and urban rail transit tunnel that is constructed at proximity, this paper established 3D finite element models based on Chongqing Zengjiayan Tunnel and the Metro Railway Line 9 and Line 10 projects to calculate and analyze the secondary lining stress, distribution and change law of deformation of Zengjiayan Tunnel and the Metro Railway Line Tunnel. The results show that: (1) The main risk of the Zengjiayan Tunnel is that the tunnel body might displace in the excavation and the surrounding rock stress could possibly change. The forces undertaken by the main structure of the cross-section are calculated and analyzed based on the shallow buried tunnel. Accordingly, the horizontal and vertical displacement limit and relative displacement meet the relevant specification; (2) Zengjiayan Tunnel over the lobby of Liyuchi Station, a transitional station of Line 9 and Line 10. The main risk is the displacement of the transitional channel in the excavation and changes in the stress on surrounding rocks, but the risk of self-structure excavation and support is under control.

Investigating the Effect of Soil Layering on Soil-structure Interaction under Seismic Load

Considering soil layering is a crucial and effective issue in investigating the seismicity of structures. However, previous studies have not examined the presence of a rock layer in soft soil. So, in the present paper, the effect of the rock layer in soft soil on the forces and displacements created in the low-and mid-rise steel moment frame was investigated. Thus, several numerical calculations were performed on 12 different sizes of rock layers at three different depths. Finite element models were analyzed using ABAQUS Software and considering the interaction of structure and soil. Results of the studies showed that the value of force and displacement depends on the frequency of the structure, the frequency of the soil-structure system, dominant earthquake frequency, the rock weight, and the stiffness of the structure. Two new parameters are defined that have a linear relationship with force and displacement. Results show that the thickness and length of the rock layer affect the value of force and displacement. Also, the presence of a rock layer in the soil may not be reliable and may increase the shear force by up to 27%, the axial force by up to 10%, and the moment by up to 19%. The effect of the presence of a rock layer on the displacement is more than on the force and increases the lateral displacement by up to 31% and the relative vertical displacement of the foundation by up to 59%.

Влияние формы погруженного тела на характер его движения вблизи свободной поверхности жидкости

Object and purpose of research. This paper discusses the tests with submerged models of different shape moving near the free surface in the test tank. The purpose of the study was to determine how relative vertical displacement and crosssection shape lift of submerged body depend on the speed of its movement at different immersion depths. Materials and methods. Model test procedure, techniques and results of model. Numerical simulation was performed in ANSYS software package. Main results. Experimental and theoretical study on cross-section shape effect of submerged body upon its wave generation, vertical lift and movement pattern near free surface. Conclusion. The results of this research will be useful for further work towards greater horizontal movement stability of submerged body at various speeds depending on its hull shape and immersion depth.

Breast biomechanics, exercise induced breast pain (mastalgia), breast support condition and its impact on riding position in female equestrians

Breast biomechanics, exercise-induced breast pain (EIBP) and performance effects in female athletes are established. Wearing sports bras during exercise reduces breast movement and EIBP. Despite the prevalence of female equestrians, little investigation of breast movement during horse riding exists, yet excessive breast movement, embarrassment and EIBP are reported. Breast movement relative to the torso is linked to EIBP, associated with magnitude and direction of forces generated. Equestrians may experience novel breast and upper-body movement patterns in response to large vertical excursions of the horse. This study aimed to establish relative vertical breast displacement (RVBD), EIBP and positional changes in three support conditions: ‘no support’, ‘low support’ and ‘high support’. Thirty-eight female equestrians rode a Racewood™ Equine Simulator in each breast support condition in medium walk, medium trot (sitting) and medium canter. Trials were filmed and analysed using Quintic® Biomechanics V29. Significant reductions in RVBD (P<0.001) and EIBP (P<0.001) were identified with increased breast support in all gaits. In medium trot (sitting) a significant reduction in range of movement (ROM) of shoulder-elbow-wrist (P<0.001) was seen from low to high support. ROM of torso-vertical angles were reduced from no support to low support (P<0.001) and further by high support (P<0.001). This reduction in ROM was significantly greater in large breasted riders (cup size DD-FF) (n=21) (P<0.001) compared to small breasted (cup size AA-D) (n=17). These results suggest that appropriate breast support positively impacts EIBP and riding position in female riders possibly enhancing performance. As RVBD and reported EIBP were not wholly comparative with results in female runners, further research is warranted to establish breast movement in equestrianism in three dimensions.

Stochastic Dynamic Response Analysis and Probability Evaluation of Subway Station Considering Subjected to Stochastic Earthquake Excitation

As a relatively new means of transportation, the subway has become an important tool for the sustainable development of many cities. Being buried deep in soil under the weight of vital infrastructure, subway stations can be vulnerable to seismic excitations. Considering the high randomness of ground motions, it is important to research the failure probability and seismic performance of the subway station based on stochastic dynamic analysis. In this paper, a probability density evolution method (PDEM) coupled with a spectral representation random function is used to analyze the stochastic dynamic response and seismic probability of a subway station. First, according to the improved power spectral density model and the seismic design code of urban rail transit structures in China (GB 50909-2014), a set of nonstationary ground motions consistent with the code spectrum are obtained. Then, a great deal of deterministic dynamic calculations for Daikai subway station considering soil–structure interaction based on elastic–plastic methods are performed. In addition, the nonlinear stochastic response analysis and the dynamic probability analysis are obtained for the subway station by solving the PDEM equation. Finally, the probability density function (PDF) and cumulative distribution function (CDF) of the subway station under stochastic earthquake excitations are obtained based on three performance indices, including drift angle in the middle column, relative vertical displacement between floor and roof, and damage area ratio (DAR). The results show that the stochastic dynamic analysis and the probability density evolution method can analyze seismic response and evaluate seismic performance of subway stations effectively. The proposed method will serve as an effective tool for the seismic design of underground structures.

Mechanical Performance of a Ballastless Track System for the Railway Bridges of High-Speed Lines: Experimental and Numerical Study under Thermal Loading.

The mechanical performance of China Railway Track System type II (CRTS II) ballastless track suitable for High-Speed Railway (HSR) bridges is investigated in this project by testing a one-quarter-scaled three-span specimen under thermal loading. Stress analysis was performed both experimentally and numerically, via finite-element modeling in the latter case. The results showed that strains in the track slab, in the cement-emulsified asphalt (CA) mortar and in the track bed, increased nonlinearly with the temperature increase. In the longitudinal direction, the zero-displacement section between the track slab and the track bed was close to the 1/8L section of the beam, while the zero-displacement section between the track slab and the box girder bridge was close to the 3/8L section. The maximum values of the relative vertical displacement between the track bed and the bridge structure occurred in the section at three-quarters of the span. Numerical analysis showed that the lower the temperature, the larger the tensile stresses occurring in the different layers of the track structure, whereas the higher the temperature, the higher the relative displacement between the track system and the box girder bridge. Consequently, quantifying the stresses in the various components of the track structure resulting from sudden temperature drops and evaluating the relative displacements between the rails and the track bed resulting from high-temperature are helpful in the design of ballastless track structures for high-speed railway lines.

Tuned viscous mass damper (TVMD) coupled wall system for enhancing seismic performance of high-rise buildings

This paper proposes an innovative coupled wall system, named the tuned viscous mass damper (TVMD) coupled wall system, for use in high-rise buildings. This novel wall system is expected to control both the lateral inter-story drifts and the floor accelerations of high-rise buildings when subjected to strong ground motions, thus enhancing their seismic resilience. The TVMD consists of a component that provides stiffness connected in series with a ball screw device that can provide large inertial and damping forces, even when subjected to small deformations. In this system, TVMDs are arranged to connect adjacent wall piers in a zig-zag configuration. Such a strategic TVMD arrangement makes efficient use of the vertical relative displacements of the adjacent walls induced by their flexural deformation to generate the motions and forces of the TVMDs. Two methods are presented for the optimal design of this system, namely, a single-mode tuning method and a multi-mode tuning method. Dynamic response analysis is conducted on a representative 15-story TVMD coupled wall system. The results of the analysis indicate that the TVMDs designed by the single-mode tuning method not only suppress the dynamic responses of the tuning mode, but also provide additional damping for the lower-order modes of the primary structure. The multi-mode tuning method shows similar performance to the single-mode tuning method if the latter is used to tune the higher-order mode. Finally, real-time hybrid simulations were conducted to examine the seismic performance of the proposed system. The test results demonstrate the advantages of the TVMD coupled wall system and indicate that the detuning effect is slight for this system, even when subjected to strong ground motions.

Dynamic analysis of railway vehicle derailment mechanism in train-to-train collision accidents

Train collision-induced derailment may result in serious casualties. This study investigates the railway vehicle derailment behaviour and explores the derailment causes in train-to-train impacts. A train-track coupled dynamic model is developed and validated. The lateral ( Yde) and vertical ( Zde) relative displacements of the wheel/rail pair are used for the derailment evaluation. The results show that the wheelset jumping derailment and the saw-tooth buckling mode may occur during the high-speed collisions. Derailment is mainly caused by car body yawing rotation and wheelset lateral and vertical displacements. Yawing and pitching motions of car body influence wheelset displacement significantly. Vehicles with the higher velocity generate more severe derailment behaviour. Under circumstance of the same train impact energy, the higher vehicle mass and greater car numbers have the stabilizing influence for reducing the derailment risk. Increasing the force on the main energy-absorbing structure which is set in the front-end crushing zone of a vehicle to dissipate the train impact energy and the damping coefficient of the secondary yaw damper can decrease the derailment risk. The train safety operation areas and derailment boundaries indicate that the reliability of the Yde criterion is higher.