Lateral Impact Tests Research Articles

Investigating the effectiveness of CFRP strengthening in improving the impact performance of RC members

Rising global rail infrastructure expansion has increased accidents involving train derailments. Reinforced concrete (RC) elements require impact-resistance enhancement to prevent structural damage or failure. While extensive research has analyzed CFRP-strengthened concrete columns under dynamic loading, further understanding of CFRP's impact on RC members is needed. Considering dynamic factors, this study investigates CFRP-RC components' performance under asymmetric impact. Components wrapped in one, four, or six CFRP layers underwent high-energy asymmetric lateral impact testing to obtain deflection-time curves. Results showed that multiple CFRP layers significantly improved impact resistance by increasing plateau force, reducing maximum deflection to 42%, and shortening duration. Longitudinal-circumferential bonding conferred better reinforcement than other arrangements. However, multiple CFRP layers increased fracture susceptibility due to severe concrete damage. An equation was derived from dynamic equilibrium principles. Finite element modeling validated experimentally was used to simulate lateral impact. Impact force, deflection, and bending moment over time were compared. Impact resistance, flexural capacity, plastic deformation, and energy absorption were also examined. Internal force distribution and development were analyzed. A simplified calculation estimated maximum deflection. CFRP reinforcement methods' effects were examined. Results indicate CFRP elevates plateau impact force and average bending moment while significantly decreasing deflection and duration, greatly enhancing impact resistance and flexural bearing capacity.

Effects of the Number of Layers and Thickness Ratio on the Impact Fracture Behavior of AA6061/AA7075 Laminated Metal Composites

The initial thickness ratio and number of layers of dissimilar metal components greatly influence the impact performance of laminated metal composites. In this paper, positive and lateral impact tests of 5-layer composite sheets with thickness ratios of 3:1, 1.35:1, and 1:2 and 80-layer composite sheets prepared by ARB (accumulative roll bonding) were conducted to study the influences of the thickness ratio and layer number on the impact fracture behavior of composite sheets. The results showed that the higher the proportion of AA7075, the higher the bending strength of the AA6061/AA7075 laminated composite sheet; compared with the 5-layer composite sheet, the side impact performance of the 80-layer composite sheet is obviously improved, and its side impact strength, energy absorbed in the crack initiation stage, and crack propagation stage are better than those of the 5-layer composite sheet. In addition, the toughening mechanism of the 80-layer composite sheet is mainly that the increase in the number of layers makes the cracks deflect more frequently. Under the rapid impact load, the impact energy absorbed by the sample increases with the increase in the number of layers.

Experimental study on dynamic shear-behavior of H-shaped SRC columns under lateral impact loading

This paper investigates the impact resistance and damage mechanism of steel reinforced concrete columns under lateral impact loading using experimental and numerical studies. First, six specimens were subjected to impact testing utilizing a horizontal lateral impact test device. Then, the effects of impact velocity, boundary condition, and impact direction on the impact response of specimens were investigated. The damage development, final damage pattern, impact force-time history, lateral displacement, and concrete strain were obtained to figure out the damage mechanism of steel reinforced concrete columns. The test results show that all specimens exhibit brittle shear damage patterns. As the impact velocity increases, the local brittle shear damage becomes more pronounced. Following experimental investigation, a finite element model was established and validated against the experimental results. The distribution of impact energy among different components and the effect of axial load on the impact resistance of specimens were obtained using finite element models. It was found that concrete dissipates the most energy among different components. However, the percentage of energy dissipated by the profiled steel increases with the increase in impact velocity, meaning that the insertion of profiled steel into concrete elements can effectively enhance the impact resistance of the structure. It was also found that the steel reinforced concrete column is more prone to local shear damage in a large range of axial load.

Tests and deflection calculation method for circular concrete-filled steel tubular columns under very low-elevation lateral impact loads

An experimental investigation of circular concrete-filled steel tubular (CFST) columns subjected to very low-elevation lateral impacts was performed. Six circular CFST members were prepared for lateral impact tests according to the typical CFST columns in high-speed railway stations in China, and the impact location was at the height of the 2/9 column. The tests had three variables: the thickness of the steel tube, the impact velocity, and the axial load. The failure modes were determined in the tests, along with the time histories of the impact force and the deflection at the impact location. A finite-element analysis was performed to examine the effects of the axial load and scaling on the maximum deflection. The results show that with the increase of axial compression ratio, the impact resistance of the member first increases and then weakens. According to the travelling plastic hinge theory, a three-stage rigid plastic mechanical model was employed to describe the impact process, in which the impact location was at the non-mid-span, and a deflection calculation method for CFST applicable to any impact position was developed. A comparison with the test results indicated that deflections can be calculated with reasonable accuracy using the proposed method.

Lateral impact test and inertial force of concrete-filled steel tube column

The mechanical behavior of concrete-filled steel tube (CFST) subjected to lateral impact was studied by drop hammer test and finite element method (FEM). Lateral deformation occurred when the midspan of CFST was impacted by a drop weight. Two plastic hinges were formed in the mid-span and near the fixed support, respectively. The numerical and experimental results were compared to ensure that the numerical model was reasonable for investigating the stress development, damage, and inertial force of the CFST column. The effects of the impact velocity, impact mass, cross-sectional steel ratio, and boundary conditions on the inertial force of the CFST column were analyzed. During the impact process, the maximum stress was at the steel tube part of the impact location and the fixed support, while the other parts were still in the elastic or elastoplastic stages. The region under restraint at the fixed end of the CFST column exhibited the first signs of concrete core damage under tension, followed by the region near the location of the impact at midspan. At the peak impact force (Fp), the impact velocity had a considerable influence on the distribution of inertial force of CFST, while the impact mass and cross-sectional steel ratio had no discernible impact on the inertial force at the Fp, and boundary conditions had little impact on the distribution of inertial force. Based on a research of the inertial force at the Fp, a simple mechanical model of the inertial force was built.

Lateral impact resistance of full-scale concrete-filled weathering steel tube columns

This paper conducted lateral impact tests on 10 concrete-filled weathering steel tubular (CFWST) columns and studied the effect of prestressing on their resistance to lateral impact. The results indicate that by using prestressed cantilever members, the impact resistance of the column can be significantly improved. This is mainly due to the reduction of tensile stress level in the steel tube at the fixed end of the cantilever column and of the overall plastic deformation of the member, which is achieved through the application of prestress. Furthermore, the test process was also simulated numerically. Based on verifying the correctness of the numerical simulation, the parameters of the full-scale model are analyzed. The impact resistance of the model was evaluated by considering various factors such as impact angle, impact point height ratio, prestress ratio, width-thickness ratio, slenderness ratio, and mass ratio. Based on these analyses, empirical formulas for the lateral ultimate displacement and bending moment of the cantilever members were derived. Particularly, considering the difference in yield strength between tension and compression sides, the theoretical calculation of plastic limit bending moment of concrete-filled square steel tubular members is modified. Additionally, the damage level of the component is defined, and the damage limit value of the concrete-filled steel tubular cantilever column is given based on the different damage grades. On this basis, considering the bending bearing capacity and displacement response of the component, an impact resistance design approach based on the performance of the component is proposed.

Assessment on concrete constitutive models for numerical simulations of vehicular collisions with RC bridge piers

Accident statistics showed that vehicular collision caused serious shear damage or failure of reinforced concrete (RC) bridge piers and even resulted in overall collapse of bridge structures. For the resistance evaluation of RC components under impact loads, numerical simulations have been performed by adopting different concrete constitutive models and obtained different results, e.g., Karagozian and Case Concrete (KCC) model and Continuous Surface Cap (CSC) model widely used, as well as Kong-Fang (KF) model recently proposed. This study mainly evaluates the accuracy of the above three concrete constitutive models in numerical analyses of vehicular collisions with RC bridge piers. Firstly, basic mechanical behaviors of these models are systematically compared based on single element simulations. Then, the scope of investigation is extended to component level by simulating a drop hammer test on RC beam and a lateral impact test on RC column, and the dynamic behaviors of impacted RC components are deeply compared. Finally, these models are further compared at structure level through performing the refined numerical simulation of a real truck colliding with a prototype bridge and evaluating its global structural behaviors and damage. The results show that, (i) KF model well reflects the post-peak softening behavior, stable strain-rate effect and independence of mesh size of concrete materials under uniaxial loading conditions at different loading rates; KCC and KF models both capture the brittle to ductile transition of concrete materials with increasing confinement pressure; (ii) KF model yields a better prediction in dynamic responses and damage characteristics of impacted RC beam and column, while KCC and CSC models both overestimate the damage degree; (iii) KF model better simulates the shear failure of RC pier in the real accident and provides the reasonable structural dynamic responses, but KCC and CSC models much underestimates the damage degree of impacted bridge pier and adjacent components.

Influence of stirrup ratio on vehicular impact resistance of double-column RC bridge piers

Vehicular collision is a typical lateral consecutive impact process. Under such an impact process, reinforced concrete (RC) bridge piers commonly suffer shear failure or punching-shear breakage, which could further cause the collapse of the bridges, especially for the simply-supported double-column RC bridges. The current work experimentally and numerically investigates the influence of stirrup ratio on the lateral consecutive impact resistance of double-column RC bridge piers (DCBPs). Firstly, a scaled lateral consecutive impact test is conducted on three DCBP specimens (containing impacted pier, adjacent pier and bent cap) to examine the influence of stirrup ratio on the dynamic behaviors at component level. Then, finite element (FE) models of the impact test are established and validated against the experimental results. Finally, refined numerical simulations of light, medium and heavy trucks colliding with a prototype simply-supported double-column RC bridge are performed at structural level to analyze the influence of stirrup ratio on dynamic shear capacity and deformation of the impacted RC piers, and anti-collapse performance of the bridges. The results derive that, (i) The impacted piers exhibit shear failure at the impact location, and the damage degree is significantly reduced with increasing stirrup ratio. However, the damage degree of adjacent piers and bent caps is not obviously influenced by the change of stirrup ratio; (ii) A higher stirrup ratio effectively achieves less stiffness degradation and smaller lateral deformation of the impacted piers under the first impact, that allows DCBPs to resist a higher second impact force; (iii) The deformation shape of the impacted piers is changed from the localized deformation to the global deformation with the increase of stirrup ratio, while such a variation does not occur to the adjacent piers; (iv) As the stirrup ratio increasing, the simply-supported double-column RC bridge can withstand a higher dynamic shear demand induced by vehicular collisions, and therefore decreases the global damage and collapse probability, especially when subjected to heavy truck collisions.

Lateral impact performance of wire ropes

Wire ropes are often used in flexible barriers or road engineering to resist lateral impact because of their good reliability, high economy, and construction convenience. However, their application under lateral impact lacks a systematic design approach. In this paper, to ensure the safe use of the structure, the lateral impact test of single wire ropes and wire rope nets is carried out, and the strain, displacement, and acceleration response are analyzed. In addition, the tensile mechanical properties of wire rope strands are determined through static tensile mechanical properties tests, which provide reasonable parameters for the constitutive model used in numerical simulations. Furthermore, considering the influence of wire rope pre-tension ratio, span ratio, and mass ratio, empirical formulas for longitudinal peak tensile force and lateral peak displacement are given. The results show that the wire rope mainly occurs local abrasion at the impact point, fracture, and end connection failure. It is worth noting that when the dimensionless lateral peak displacement (ωm) reaches 0.089, the wire rope breaks. Moreover, according to Lagrange Green’s strain theory, a theoretical calculation formula for the mid-span lateral limit displacement of wire rope under pre-tension is derived and compared with the simulated values of test members. Consequently, according to the damage degree of wire ropes, the damage limit value is determined. Finally, considering the tensile capacity of wire ropes and their displacement responses, a limit state function is proposed to evaluate the damage of existing components or to design new components.

Behavior of axially loaded high-strength steel circular hollow section tubes under low velocity lateral impact

High-strength steel has been widely used in large-span and high-rise structure engineering in recent years because it can improve the mechanical performance of building structures and reduce their self-weight. In this study, a lateral impact test using a drop hammer was conducted on 22 high-strength steel circular hollow section (CHS) tubes with axial preloading. The test parameters included the impact energy, tube diameter–thickness ratio, axial compression ratio, and shape of the hammerhead. The failure modes and entire impact process, including the impact force, displacement, strain, and axial force histories of the specimens, were obtained. A finite element (FE) model of the high-strength steel CHS tube preloaded by axial force (including compression and tension) under lateral impact was established using the nonlinear finite element analysis (FEA) software ANSYS/LS-DYNA. After verifying the accuracy of the FE model by comparison with the test results, a parameter analysis was conducted to reveal the influence of the impact energy, diameter–thickness ratio, axial compression ratio, axial force direction, and shape of the hammerhead on the dynamic response of the high-strength steel tube under lateral impact based on the test and FE results of the failure mode, impact force, displacement and energy histories, and residual stress.

Field test and numerical simulation of a full-scale RC pier under multiple lateral impacts

In recent years, the frequent occurrence of vehicle-pier collision accidents have highlighted the necessity of the research on the impact resistance of bridge piers; but until now, most of the studies employed numerical simulations or indoor reduced-scale tests, while the collision tests regarding full-scale reinforced concrete (RC) piers with actual foundations are still scarce. In order to obtain the most realistic impact responses and damage characteristics of RC pier, six successive lateral impact tests on a full-scale RC single-column pier with a monopile foundation were conducted in this study based on a self-designed large-size slide device and a rigid model vehicle. The mass of the model vehicle was 2205 kg and the impact velocity ranged from 3.17 m/s to 8.22 m/s. The tests obtained valuable test data such as vehicular impact forces, and lateral displacements, accelerations and damage pattern of the RC pier under all the six collision trials. Furthermore, finite element (FE) simulations were also performed and validated against the test results, where several problems of the commonly-used FE simulation techniques are revealed. In addition, the influences of multiple (successive) impacts on the impact forces and dynamic behavior of the pier are also discussed in this paper. This study provides valuable experimental data for the current research on RC piers subjected to vehicle collisions, and also references for the numerical simulations and theoretical analysis of RC columns under multiple lateral impacts.

Vehicular Impact Resistance of FRP-Strengthened RC Bridge Pier

As-built bridge piers are likely to be subjected to vehicular collisions, causing severe damage to the bridge substructure and even resulting in the collapse of the entire bridge. This study aimed to evaluate the effectiveness of fiber-reinforced polymer (FRP) strengthening in enhancing the vehicular impact resistance of as-built bridge piers. A typical local, refined finite-element (FE) model of a simply supported two-span, double-column, reinforced-concrete (RC) bridge was established. The adopted material constitutive models and the FE analytical approaches were then validated through reduced vehicle model lateral impact tests on bare and carbon fiber–reinforced polymer (CFRP)-strengthened RC columns. The effective schemes for FRP strengthening of bridge piers against vehicle impact are discussed from the aspects of fiber orientation, number of layers, and strengthened height as well as by FRP type. Based on the FRP strengthening scheme, 48 vehicle–bridge collision scenarios were designed to evaluate the collapse of bridges with/without FRP-strengthened piers. It was found that (1) external FRP wrapping can effectively enhance vehicular impact-resistance of as-built bridge piers (e.g., reducing the degree of damage and deformation of the impacted pier); (2) for typical bridge piers, the effective strengthening scheme comprised a fiber orientation of 0° in reference to the circumferential direction, a 3-m strengthened height, and four-layer CFRP wrapping; (3) compared with bare bridge piers, FRP-strengthened piers could improve the vehicular impact-resistant safety redundancy of as-built bridges and, to some extent, avoid bridge collapses under truck collisions at high speed. Furthermore, through introducing the dynamic increase factors of concrete strength, reinforcement rebars, and FRP, and considering the nonuniform distributions of the strain rate of FRP-strengthened bridge piers caused by vehicular collision, the dynamic shear capacity of strengthened bridge pier was formulated.

Effectiveness of CFRP shear-strengthening on vehicular impact resistance of double-column RC bridge pier

As-built reinforced concrete (RC) piers could be subjected to vehicular collisions in their whole service life, resulting in severe shear failure of piers and even catastrophic damage to entire bridges. Considering that the vehicular collision is the lateral consecutive impact process including bumper, engine and cargo impacts, the effectiveness of CFRP shear-strengthening of double-column RC bridge piers (DCBPs) to resist the lateral consecutive impact needs to deeply studied. Firstly, the reduce-scaled vehicle model lateral consecutive impact test is performed on a bare pier, a CFRP shear-strengthened slight-damaged pier and a CFRP shear-strengthened intact pier in DCBP specimens. The influence of CFRP strengthening on the damage evolution, failure mode and transient dynamic responses and energy dissipation are examined. Then, numerical simulations of the present impact tests are conducted to validate the adopted finite element analyses (FEA) approach. Furthermore, based on the validated FEA approach, a local refined finite element (FE) model of a prototype simply-supported two-span double-column RC bridge is established, and six numerical simulations of typical light, medium and heavy trucks colliding with the entire bridge with/without CFRP strengthened pier are performed. Based on the simulated results, the effectiveness of CFRP strengthening on the dynamic shear demand, dynamic bending moment and deformation of the impacted pier, as well as the damage/failure and collapse of the entire bridge are further evaluated and discussed. It is found that: (i) compared with brittle shear failure of the bare pier, the strengthened slight-damaged and intact piers both have the excellent lateral consecutive impact resistance with exhibiting shear-flexural and ductile flexural failure modes, respectively; (ii) suppression of the shear damage evolution is beneficial to both strengthened slight-damaged and intact piers to have the higher damage and defamation tolerance to dissipate more impact energy; (iii) the strengthened intact piers in the prototype bridge model can withstand the higher dynamic shear demand and dynamic bending moment but experience the less deformation and damage; (iv) since the deformation and damage of strengthened intact pier in the prototype bridge model under actual vehicular collision are significantly reduced, the vehicular impact resistance and collapse resistance of entire bridge can be improved.

Development and Evaluation of Top-Mounted Sockets for Weak-Post, Midwest Guardrail System on Culverts

New top-mounted sockets for use with the weak-post, Midwest Guardrail System (MGS) on low-fill culverts were developed and evaluated. The system was adapted from the MGS bridge railing for attachment to the top slab of a concrete box culvert. Three design concepts were developed and evaluated through dynamic component testing. Both lateral and longitudinal impact tests were conducted on the design concepts while mounted to simulated concrete culverts. Two concepts, a cylindrical concrete foundation and a steel tube socket assembly, proved strong enough to withstand the impact loads transferred from the posts without sustaining significant damage or displacements. However, the third concept, a concrete slab, fractured and allowed the sockets to rotate back without developing the post bending strength. Thus, only the cylindrical concrete foundation and the steel tube socket assembly in combination with the weak-post, MGS were determined to be crashworthy according to the Manual for Assessing Safety Hardware (MASH) Test Level 3 safety criteria. The new top-mounted, socketed, weak-post, W-beam MGS for low-fill culverts has multiple advantages over other guardrail treatments for culverts. The guardrail system has an unrestricted system length and does not require a transition when attached to the MGS. The top-mounted system can be placed parallel to the roadway with a constant lateral offset regardless of the position and orientation of the culvert headwall. Additionally, the attachment configurations were designed utilizing epoxy anchors, enabling the system to be installed on new or existing culverts. Finally, the sockets remain undamaged during impact events, allowing for quick repairs.

Study on the nonlinear response and shear behavior of RC columns under lateral impact

In the present study, in view of the problem of nonlinear response caused by vehicle-RC pier collision, a new test system which can realize lateral impact is proposed, and two types of 1:3 scale RC components in five groups are subject to the lateral impact test at a velocity of 4.5 m/s. The system’s design characteristics represent the effect of stirrup spacing and axial compression ratio on the dynamic response of RC columns. In addition, the nonlinear response results of RC columns, such as impact force, acceleration, lateral displacement, failure mode and degree, are given in the test. Digital Image Correlation (DIC) technology is applied to the test. Next, the lateral strain response of RC columns during impact is measured, and the strain change process in every representative region is calculated. The data outlined in this study provide a reasonable basis for evaluating the shear capacity of RC columns and developing a finite element model (FEM). Finally, a typical FEM of vehicle-pier collision scenario is developed, while an improved equation for calculating the axial compression ratio-shear increment and a simplified calculation value of dynamic shear capacity of the RC pier are proposed.

Experimental Study on the Impact Resistance of Closed‐Cell Aluminum Foam Protective Materials to RC Piers under Lateral Impact

In this study, the lateral impact tests of six RC piers which were protected by closed‐cell aluminum foam (CCAF) were carried out by making use of an ultrahigh drop hammer horizontal impact test system. The protective effects of CCAF with different densities on the piers were then analyzed. The data regarding the piers’ impact force, displacement, reinforcement strain, and crack and damage development were mainly collected during the experimental testing processes. The results indicated that, when the impact energy was less than 7258 J and the density of the CCAF was 0.45 g/cm3, the cumulative impact force and displacements of the piers decreased by 67% and 35%, respectively. Therefore, it was considered that the CCAF with a density of 0.45 g/cm3 had displayed the best protective effects at that stage. It was also observed that when the impact energy was greater than 7258 J and the density of the CCAF was 0.55 g/cm3, the cumulative impact force and displacements of the piers decreased by 25% and 18%, respectively. Therefore, the CCAF with a density of 0.55 g/cm3 had displayed the best protective effects at that stage. Furthermore, under the conditions of constant accumulative impact energy, the protective effects of CCAF on the piers were observed to be weakened if it entered the densification stage too early and high‐yield platforms were formed due to the density levels becoming too high. However, it was found that reasonable density and thickness increases could effectively delay the entry of CCAF into the densification stage, which effectively reduced the shearing effects which occurred when the impact speeds were too high, thereby preventing the shear failure of the piers.

An evaluation study on the cumulative impact damages of reinforced concrete piers based on modal frequencies

In this study, in order to accurately evaluate the cumulative impact damages undergone by concrete piers, lateral impact testing of reinforced concrete piers was carried out using an ultra-high drop hammer test system to impose damages. Then, modal frequency tests of the impacted piers were conducted one by one. It was found that, according to such parameters as the reinforcement stress and strain levels, crack widths, column top displacements, and so on, which had been obtained from experimental results, and based on the existing research results and codes, the evaluation criteria of the cumulative impact damages of reinforced concrete piers based on modal frequencies could be proposed for the bending failure components. In addition, it was confirmed that when the aforementioned evaluation criteria was adopted, timely nondestructive testing could be effectively conducted for damaged piers, and the status of the piers could be quickly determined in order to ensure the safety of passing vehicles.

Behavior of RC Beams Strengthened Using Steel-Wire–Carbon-Fiber-Reinforced Plates

The steel-wire–carbon-fiber-reinforced plate (SCFR plate) is a relatively new strengthening technology for concrete structures. In this paper, a series of lateral impact tests on SCFR plates and conventional carbon-fiber-reinforced plates (CFR plates) were first performed, followed by tensile tests of both the SCFR plates and the CFR plates. It is found that the SCFR plates can provide the same level of tensile strength as CFR plates, whilst having evident advantages in terms of better ductility and lateral resistance. It is also found that increasing the amount of the steel wire can improve the lateral resistance of the SCFR plate. In addition, the SCFR plate shows the advantage of a reduction in lateral damage, which is commonly experienced by CFR plates during transportation, construction, and maintenance. In the second stage of the research, flexural tests of both SCFR and CFR plate-strengthened reinforced concrete (RC) beams were performed. The failure modes and crack patterns of the RC beams were investigated. Results show that the SCFR plate-strengthened beam exhibits enhanced ductility compared to that strengthened by traditional CFR plates, thereby enhancing the flexural capacity of the RC beams. On the basis of the test results, a formula is designed to predict the flexural capacity of SCFR plates; good agreement is achieved.

Response Ratio Development for Lateral Pendulum Impact with Porcine Thorax and Abdomen Surrogate Equivalents.

There has been recent progress over the past 10 years in research comparing 6-year-old thoracic and abdominal response of pediatric volunteers, pediatric post mortem human subjects (PMHS), animal surrogates, and 6-year-old ATDs. Although progress has been made to guide scaling laws of adult to pediatric thorax and abdomen data for use in ATD design and development of finite element models, further effort is needed, particularly with respect to lateral impacts. The objective of the current study was to use the impact response data of age equivalent swine from Yaek et al. (2018) to assess the validity of scaling laws used to develop lateral impact response corridors from adult porcine surrogate equivalents (PSE) to the 3-year-old, 6-year-old, and 10-year-old for the thorax and abdominal body regions. Lateral impact response corridors were created from 50th adult male PSE pendulum lateral impact T1, T14, and L6 accelerations and pendulum impact force time histories for the thorax and abdomen testing performed. The ISO 9790 scaling technique using length, mass, and elastic modulus scale factor formulas were used in conjunction with measured swine parameters to calculate scale factors for the PSE. In addition to calculation of pertinent test scale factors, response ratios for the pendulum impact tests were calculated. The scaling factors and response ratios determined for the porcine surrogates were compared to the already established ISO human lateral pendulum impact response ratios to determine whether a consistent pattern over the age levels described for the two sets of data (human and swine) exists. The actual lateral impact pendulum data, for both thoracic and abdominal regions, increases in magnitude and time duration from the 3-year-old PSE up to the 50th male PSE. This increase in magnitude and time duration is comparable to the human response corridors developed based on an impulse-momentum analysis and the elastic bending modulus derived from human skull bone. This pattern in the human impact response corridors was observed in the response ratio values and the swine response data. Based on the current study's findings, when utilizing the elastic modulus of human skull bone presented previously in research, thoracic and abdominal lateral pendulum impact response of PSE follows the general scaling laws, based on the impulse-momentum spring-mass model. The thoracic and abdominal lateral pendulum force impact response of PSE also follows the human scaled impact response corridors for lateral pendulum impact testing presented in previous research. The overall findings of the current study confirm, through actual swine testing of appropriate weight porcine surrogates, that scaling laws are applicable from the midsized-male adult down to the 3-year-old age level using human skull elastic modulus values established in previous research.

Rib kinematics analysis in oblique and lateral impact tests

Understanding thorax kinematics and rib breaking mechanisms in conditions of oblique and lateral impact is crucial in safety systems development. To increase knowledge level on this subject, simulation and experimental tests are necessary. The purpose of this study was to obtain single rib kinematics in the case of oblique and lateral impact conditions using numerical simulation approach. Two impact tests using human body model of a 50th percentile man (THUMS v4.0.1 AM50) were performed in LS-Dyna R7.1.1. Impactor was a rigid cylinder with a diameter of 152 mm, and velocity equal to 6.7 m/s. Impact angle measured to sagittal plane was 30 and 90°, respectively in oblique and lateral impact case. Kinematics of ribs from 3rd to 6th were analyzed. Results shown significant similarities between oblique impact and kinematics of ribs tested in frontal impact conditions in the literature, with maximal costochondral joint displacement relatively to costovertebral joint varying from 65.4 mm (3rd rib) to 82.0 mm (5th rib). Deformation of rib in lateral impact conditions was different than during oblique impact test, with distinctive "flattening" approximately in the middle of the rib. Maximal relative displacement varies from 16.4 mm (6th rib) to 26.6 mm (5th rib) and its location depends on the analyzed rib. Oblique impact scenario may be simulated for the single rib on an experimental way using set-up of the frontal impact. Experimental simulation of the lateral impact for the single rib should not use the same set-up, as the kinematics analysis showed significant differences between simulated cases.