Single Impact Research Articles

Effect of temporal pattern of impact sound on annoyance: Children's impact sounds on the floor

In this study, psychoacoustic experiments are performed with sound stimuli simulating children running in order to investigate the psychoacoustic effect of the duration, number of impacts, and level variation of the impact sound. For the sound stimuli, the jumping sound of an eight-year-old child is recorded in a test building similar to a real apartment building. Using the recorded single impact sound (SIS), eight different multi-impact sources are produced, which simulate the sound of children running by varying the duration, number of impacts, and level variation. Additionally, a single-impact source with different A-weighted maximum sound pressure levels (57, 62, 67, 72, 77 dB in LiA,Fmax) and multi-impact source (57 dB in LiA,Fmax) are randomly paired. In the psychoacoustic experiment, subjects are asked to select the more annoying sound stimulus by comparing the multi-impact source and single-impact source. From the experiment, we note that for longer duration and larger number of repetitions of the impact sound, the sound is perceived as more annoying by the subjects. In the case of the level variation of the impact sound, the annoyance is determined by the total energy level rather than the maximum sound pressure level. These results revealed that findings in the previous studies using artificial noise or tone can be applied to impact sound generated in a real situation. This study suggests that rather than maximum level, evaluation indices that can reflect the duration and energy level of the impact sound are appropriate for impact sounds which exhibit random temporal patterns.

Characterising Fickian diffusion on the surface of a sphere

• Two-dimensional Fickian charge diffusion over a sphere located on an electrode. • Charge is injected at the sphere-electrode contact. • Modelling relates to single entity impact experiments. • Log-log flux-time transient reveals the changes in the diffusion regime. • Diffusion regimes embrace: convergent, divergent, linear and thin layer. Single-entity electrochemical analysis involving Fickian charge diffusion over the surface of a (truncated) sphere is explored via numerical simulation, mimicking the case where an insulating particle covered with an electroactive adsorbed layer impinges on an electrode. The ever-changing shape of the flux-time transient as the diffusion regimes change over the surface of the sphere from the point of charge injection are characterised with the use of the recently introduced diffusion indicator, α , [Haonan et. al., J. Electroanal. Chem. 855, 113602]. The indicator is shown to illuminate, with clarity, the change of diffusion from divergent near the point of injection through linear at the sphere circumference to convergent before being limited by the thin-layer effect as the surface of the sphere is fully oxidised or reduced. Truncated spheres are also examined and characterised along with diffusion under model ‘thin layer’ conditions.

A Hard Sphere Model for Bimolecular Recombination of Heavy Ions

We propose a hard sphere model of bimolecular recombination RM+ + X– → MX + R, where M+ is an alkali ion, X– is a halide ion, and R is a neutral rare gas or mercury atom. Calculations are carried out for M+ = Cs+, X– = Br–, R = Ar, Kr, Xe, Hg, for collision energies in the range from 1 to 10 eV, and for distributions of the RM+ complex internal energy corresponding to temperatures of 500, 1000, and 2000 K. The excitation functions and opacity functions of bimolecular recombination in the hard sphere approximation are found, and the classification of the collisions according to the sequences of pairwise encounters of the particles is considered. In more than half of all the cases, recombination occurs due to a single impact of the Br– ion with the R atom. For the recombination XeCs+ + Br–, the hard sphere model enables one to reproduce the most important characteristics of the collision energy dependence of the recombination probability obtained within the framework of quasiclassical trajectory calculations.

Single Vibroacoustic Impact Effect of Singing Bowls over the Psycho-Emotional State and Cardiovascular System Work

This article presents a two-stage study result of the author's method of vibroacoustic massage using singing bowls application. At the first stage, the effect of vibroacoustic massage single application over psycho-emotional characteristics was studied. 19 studied volunteers took part in our study. The testing results before and after exposures were compared according to the WAM (Weighted average mark), Zung, and Spielberg-Khanin tests. The study of the psycho-emotional sphere showed that after the vibroacoustic massage procedure, the indicators of "well-being" and "activity" of the WAM test significantly improved (p = 0.002). In addition, the depression level determined by the Zung test, personal anxiety indicators (p = 0.004), and situational anxiety ones (p = 0.028) decreased. At the second stage, 62 volunteers were divided into two groups. The first group underwent a vibroacoustic massage session according to the patented author's method. The second group received only acoustic exposure using only singing bowls. Differences in the Kerdo index were revealed in the dynamics, and in the first group, the changes were less significant than in the second one. Changes in heart rate variability characteristics for both groups were similar: there was an increase in parasympathetic influences at rest and during the orthostatic test (increased levels of RMSSD (Root Mean Square of Successive Differences), NN50, pNN50) and a decrease in sympathetic effects at rest and their slight increase with orthostatic loading (TINN, RR triangular index). The dynamics were more significant in the first group that received a vibroacoustic massage session. When assessing changes in the neurovegetative regulation levels activity of the heart rhythm, the main difference was associated with very low-frequency waves power dynamics during the orthostatic test. Thus, vibroacoustic massage using singing bowls improves the psycho-emotional state, reduces depression and anxiety, and increases Parasympaticus (autonomic nervous system) activity.

Mechanism of action of yoga on prevention and management of type 2 diabetes mellitus: Narrative review

BackgroundResearch in India has recognized Type 2 Diabetes Mellitus (t2dm) and prediabetes (pdm) as psychosomatic metabolic endocrine disorders characterized by glycemic disharmony. This review aimed at collating information from published e-papers on mechanism of action (MOA) of yoga therapy(YT) and integrated approach of yoga therapy (IAYT) on pdm and t2dm. MethodContent on YT and the MOA on prevention and management of t2dm were extracted from online sources such as PubMed, Google Scholar, Cochrane library and Library genesis. This review included 58 articles related to prediabetes, t2dm, pre-diabetes to t2dm conversion, mechanism of action of Yoga, Yoga and t2dm, prediabetes and yoga. Articles related to type 1 diabetes, diabetes insipidus and gestational diabetes were excluded. ResultCurrent scientific review resulted in understanding the different mechanisms involved in rejuvenating effect of Yoga as YT and IAYT in prediabetes and t2dm. However, the various mechanisms by which the interventions work are understood either through a single or combined impact on regaining autonomic balance, vagal modulation, regulation of hormones and thereby attaining glycemic control. Moreover, these mechanisms are the forthcomings of the cross talk between brain, mind and body systems under branches of neurophysiology, neuroendocrinology, psychophysiology, psycho neuroendocrinology and/or neuropsychology. ConclusionEvidence sought from published research works proclaim YT based life style modification for prevention and management of t2dm. Summing up, the effect is stipulated based on the approach, method of practice, time of the day, belief and dedication of the practitioners.

Continuous twice-impact analysis of steel parking structure columns

In this study, two impact tests are performed on a one-fifth scaled parking structure to obtain their columns' failure modes and response. A numerical model is developed to simulate the experiment, which considers the effects of the damage evolution and material fracture. Additionally, serial numerical analyses of the two impacts with constant total energy are conducted based on the validated model. The influence of the energy allocation between the two impacts on the impact force, residual displacement, and residual kinetic energy are investigated. An assessment method is proposed for the damaged column. The results show that the shape change and material hardening are the main reasons that affect the impact resistance of the damaged column. When the column is damaged, its robustness against the second impact is improved. With a constant total energy, the damage degree of the column caused by the single impact is larger than that of the two impacts. The effect of energy allocation on the residual displacement is 4.6% to 8.6% in the numerical calculations. The proposed assessment method can serve as a basis for future evaluation of the damaged column.

Predictive design of impact absorbers for mitigating resonances of flexible structures using a semi-analytical approach

Analytical conditions are available for the optimum design of impact absorbers (or Vibro-Impact Nonlinear Energy Sinks) for the special case where the host structure is well described as a rigid body. Accordingly, the analysis relies on the assumption that the impacts cause immediate dissipation in the contact region, which is modeled in terms of a coefficient of restitution (Newton’s impact law) that is assumed to be known and fixed. When a flexible host structure is considered instead, the impact absorber not only dissipates energy at the time instances of impact, but, and perhaps more importantly, it inflicts nonlinear energy scattering between structural modes. Hence, it is crucial to account for such nonlinear energy transfers yielding energy redistribution within the modal space of the structure. In the present work, we develop a design approach for flexible host structures. We consider the case of a forced excitation near primary resonance with a well-separated mode. We demonstrate that the time scales of the impact and the resonant vibration can be decoupled. On the long time scale, the dynamics of the host structure can be properly reduced to the fundamental harmonic of the resonant mode. A light impact absorber responds to this enforced motion, and we show that the conventional Slow Invariant Manifold of the dynamics is recovered for the commonly considered regime of two symmetric impacts per period. On the short time scale of the impact dynamics, the contact mechanics and elasto-dynamics must be finely resolved. We show that it is sufficient to run a numerical simulation of a single impact event with representative pre-impact velocity. From this short-time simulation, we derive an effective modal coefficient of restitution and the properties of the contact force pulse, needed to approximate the behavior on the long time scale. We derive a closed-form expression of the periodic resonant response and establish that the design problem can be reduced to four dimensionless parameters. We demonstrate the approach for the numerical example of a cantilevered beam with a spherical impact absorber. We conclude that the proposed semi-analytical procedure enables deep qualitative understanding of the problem and, at the same time, yields a quantitatively accurate prediction of the optimum design.

A simultaneous dual-polarity mass spectrometer with electron start for MeV-SIMS

The Capillary Heavy Ion MeV-SIMS Probe (CHIMP) at ETH Zürich has been redesigned with a second mass spectrometer and symmetric extraction to enable simultaneous analysis of positive and negative secondary ions. Secondary electrons are deflected within the negative spectrometer and detected independently. The fast secondary electron signal is used as a start signal for both Time-of-Flight mass spectrometers.The new setup enables the simultaneous acquisition and analysis of both secondary ion polarities emitted under identical conditions from the same sample location. This allows to study correlations between secondary ions of different polarities emitted from a single primary ion impact. Measurements with small primary Cn cluster ions show the influence of cluster size on the multiplicity of secondary ion emission. Furthermore, a cluster effect in the ratio between positive and negative ion yields of corresponding secondary ion species is identified, with the ratio approaching parity for larger cluster sizes n.

High-speed impact of micron-sized diesel drop trains—Splashing dynamics, secondary droplet formation, and effects of pre-existing film thickness

This work investigates surface impingement of monodispersed diesel drop trains using computational simulations. The three-dimensional simulations include high-speed impact of micrometer-sized fuel drops onto initially dry and wetted stainless steel substrates. The drop size and impact velocity are representative of fuel injection conditions in internal combustion engines (ICEs). The drop trains serve as a simplified representation of fuel spray. To accurately capture the film that naturally develops on initially dry substrates, a dynamic diesel-stainless steel contact angle model was developed using experiments of single drop impact under ICE representative temperature. Simulations are presented for a highly splashing case and the effects of a pre-existing film on splashing dynamics were investigated, including the temporal evolution of splashed mass and film thickness. It was concluded that for thin films, the effect of pre-existing film thickness is less significant than in single drop impingement. Secondary droplet characterization was performed on simulation results, leading to instantaneous and time-averaged distributions of secondary droplet size, velocity magnitude, and trajectory angle. It was found that for each drop impingement, approximately 58% of the splashed mass is from the impinging drop itself, while the remainder of the splashed mass is composed of film liquid. From a high resolution case, details of secondary droplet formation are observed and three distinct phases of secondary droplet formation are identified. The detailed analysis of drop train impingement under engine-relevant conditions serves as a first step toward a robust understanding of fuel impingement and the development of cleaner and more efficient ICEs.

Quantitative Imaging of Blood-Brain Barrier Permeability Following Repetitive Mild Head Impacts.

This was an exploratory study designed to evaluate the feasibility of a recently established imaging modality, quantitative ultrashort time-to-echo contrast enhanced (QUTE-CE), to follow the early pathology and vulnerability of the blood brain barrier in response to single and repetitive mild head impacts. A closed-head, momentum exchange model was used to produce three consecutive mild head impacts aimed at the forebrain separated by 24 h each. Animals were measured at baseline and within 1 h of impact. Anatomical images were collected to assess the extent of structural damage. QUTE-CE biomarkers for BBB permeability were calculated on 420,000 voxels in the brain and were registered to a bilateral 3D brain atlas providing site-specific information on 118 anatomical regions. Blood brain barrier permeability was confirmed by extravasation of labeled dextran. All head impacts occurred in the absence of any structural brain damage. A single mild head impact had measurable effects on blood brain barrier permeability and was more significant after the second and third impacts. Affected regions included the prefrontal ctx, basal ganglia, hippocampus, amygdala, and brainstem. Our findings support the concerns raised by the healthcare community regarding mild head injuries in participants in organized contact sports and military personnel in basic training and combat.

NUMERICAL EVALUATION OF SLAB THICKNESS EFFECT ON THE IMPACT BEHAVIOR OF CONCRETE SLABS REINFORCED WITH CFRP BARS

Theoretical investigation of the nonlinear behavior of concrete slabs reinforced with CFRP bars subjected to a single impact load is presented in this paper. For predicting the impact load on a concrete slab, there are several methods, some of which are impractical or prohibitively pricey; however, due to significant technological advancements, simulation methods instead of experimental approaches have become common methods and a cost-effective matter for developing detailed responses. The purpose of this paper is to numerically investigate the effect of slab thickness on the impact response of concrete slabs reinforced with (CFRP) bars when subjected to a single impacting load, so as to well understand their behavior which are considered modern topics and rarely highlighted. Three specimens (1800×1800) mm, with three thicknesses 80, 130 and 180 mm, simply supported by their corners, have been modelled, one reference specimen of 130 mm thickness. The reference slab numerically validated with an experimental work from literature under dropping-weight of 150 kg, it was a flat-nosed rigid steel (300*300*700) mm projectile, used to apply impacting load, which is falling freely from a height of 3.26 m. To assess slab behavior, impact force-time, displacement-time and reaction force-time histories had been plotted and discussed. The analytical results showed that slab thickness is a control factor and better performance in slabs reinforced with CFRP bars, can be achieved by increasing slab stiffness via its thickness increase.

Single and Combinative Impacts of Healthy Eating Behavior and Physical Activity on COVID-19-like Symptoms among Outpatients: A Multi-Hospital and Health Center Survey.

Background: Healthy eating and physical activity are effective non-pharmacological approaches to boost immune function and contain the pandemic. We aimed to explore the associations and interactions between physical activity and healthy eating behavior with COVID-19-like symptoms (Slike-CV19S). Methods: A cross-sectional study was conducted on 3947 outpatients, from 14 February to 2 March 2020, at nine health facilities in Vietnam. Data collection included sociodemographic characteristics, healthy eating behavior (using the healthy eating score (HES) questionnaire), physical activity (using the short form international physical activity questionnaire), and Slike-CV19S. The associations and interactions were tested using logistic regression models. Results: Frequent intake of fruits (OR = 0.84; p = 0.016), vegetables (OR = 0.72; p = 0.036), and fish (OR = 0.43; p < 0.001) were associated with a lower Slike-CV19S likelihood, as compared with infrequent intake. Patients with higher HES levels (OR = 0.84; p = 0.033 for medium HES; OR = 0.77; p = 0.006 for high HES) or being physically active (OR = 0.69; p < 0.001) had a lower Slike-CV19S likelihood, as compared to those with low HES or physical inactivity, respectively. Patients with medium HES who were physically active (OR = 0.69; p = 0.005), or with high HES and physically active (OR = 0.58; p < 0.001), had a lower Slike-CV19S likelihood, as compared to those with low HES and physical inactivity. Conclusions: Healthy eating behavior and physical activity showed single and combinative impacts on protecting people from Slike-CV19S. Strategic approaches are encouraged to improve healthy behaviors, which may further contribute to containing the pandemic.

Nanoengineered Graphene-Reinforced Coating for Leading Edge Protection of Wind Turbine Blades

Possibilities of the development of new anti-erosion coatings for wind turbine blade surface protection on the basis of nanoengineered polymers are explored. Coatings with graphene and hybrid nanoreinforcements are tested for their anti-erosion performance, using the single point impact fatigue testing (SPIFT) methodology. It is demonstrated that graphene and hybrid (graphene/silica) reinforced polymer coatings can provide better erosion protection with lifetimes up to 13 times longer than non-reinforced polyurethanes. Thermal effects and energy dissipation during the repeated soft impacts on the blade surface are discussed.

Impact resistance of ultra-high performance concrete strengthened reinforced concrete beams

To improve the impact resisting performance of reinforced concrete (RC) components, three strengthening designs based on ultra-high performance concrete (UHPC) are proposed in this study. Drop hammer impact test was conducted to evaluate the dynamic response and failure modes of RC beams and UHPC strengthened RC-UHPC beams. Test specimens included two control RC beams, a RC beam with UHPC layer retrofitted on the tension surface, a RC beam with UHPC layers retrofitted on both the compression and tension sides, two RC beams with UHPC layer that was not directly attached to the tension surface, but with 5 mm gap between the interfaces. Test results showed UHPC strengthened beams had a good impact resistance. Under the impact from 641 kg weight dropping from 0.5 m, with a 15 mm UHPC layer directly attached to the tension surface of the RC beam, the crack pattern shifted from concrete spalling to diagonal shear failure, and the maximum and residual displacements decreased by 9.1% and 25.3%, respectively. RC-UHPC beams with non-attached interfaces exhibited even better impact resistance, the UHPC layer was able to develop multiple energy dissipating tensile cracks prior to failure, and the gap ensured a larger moment resistance leading to reduced beam deflections. The repeated impacts were performed on RC-UHPC beams. With the same total impact energy, the single impact was found to be more hazardous than the repeated impacts. Nonlinear finite element modelling was developed to further interpret the experimental results. With the validated numerical model, energy absorption curves, dynamic shear force and bending moment distribution diagrams were derived. Based on the experimental and numerical data, the shear mechanisms of RC beams and RC-UHPC beams were studied. The effects of non-attached spacing length, spacing depth and UHPC layer thickness were investigated in the parametric study.

Theoretical analysis of ionization of spherical aluminum alloy projectile impacting aluminum alloy target in hypervelocity impact

A two-stage light gas gun is used to accelerate the sphere 6061 aluminum projectiles to a speed range of 2.3-6.3 km/s in an almost vacuum environment. Spectrometer and pyrometer are adopted to measure the time-frequency characteristics of the collision-generated spectra when 6061 aluminum projectiles impact on 6061 aluminum targets with thicknesses varying from 1 mm to 26 mm. Based on the thermal ionization, theories of the single and the secondary collision are established. Experimental spectra show that threshold velocities of evaporation and plasma phase transition are 2.45 km/s and 4.7 km/s when spherical aluminum alloy projectile impacts on aluminum alloy target. Theoretical calculation demonstrates that neither the single impact nor the secondary impact of debris or secondary compression in the oblique direction can explain the ionization at low-speed impact. The threshold velocity of ionization, however, calculated by the combined secondary collision both in the oblique and horizontal direction during the impact of spherical projectile colliding on the target is most reasonable to explain the plasma produced by relatively low-speed hypervelocity impact.

Anti-inflammatory effects of tibial axial loading on knee articular cartilage post traumatic injury

Early therapeutic intervention to mitigate inflammatory responses following joint injury may offer a potential strategy to prevent post-traumatic osteoarthritis (PTOA). In-vitro studies have demonstrated uniaxial dynamic compression mitigates the catabolic and apoptotic responses of articular cartilage (AC) in response to mechanical injury. The objectives of this study were (1) to develop a custom device that can apply dynamic tibial axial loading (TAL) to knee AC by mimicking therapeutic, in-vitro loading conditions and (2) to investigate the potential of TAL to reduce the inflammatory response of AC post traumatic acute joint injury using an ex-vivo porcine model. A TAL device was fabricated to apply dynamic compressive loading to knee AC by combining tibial axial compressive loading with continuous passive motion. Computational analyses demonstrated that the loading condition applied to the knee by the TAL device closely simulate uniaxial dynamic compression reported in previous in-vitro studies. Following single impact injury, injured porcine knees were subjected to TAL with a magnitude of 1/4 body weight at a frequency of 1 Hz for 30 min. AC samples were harvested 8 h post injury for analysis of pro-inflammatory cytokine expression (IL-1β and TNF-α). Expression of both cytokines was upregulated following injury; however, the change was notably mitigated in the specimens subjected to TAL. Thus, TAL may be an effective and potentially, practical-to-administer early intervention strategy to mitigate rapidly occurring detrimental events following acute AC injury, potentially slowing down progression to PTOA.

New instrument based on electrostatic sensor array for measuring tribo-electrification charging due to single particle impacts.

In the processing of particulate solids, particle-particle and particle-wall collisions can generate electrostatics. This is called contact/impact/frictional electrification and can lead to many problems such as affecting powder flow and explosion hazards. It is necessary to research the tribo-electrification charging due to single particle impacts on a target as the fundamental understanding of tribo-electrification. A new impact charging test rig based on an electrostatic sensor array that can measure charge transfer caused by a single impact between a particle and a target plane has been designed and established. Combined with the electrostatic sensor array, the compressed sensing algorithm is used to estimate not only the spatial position but also the charge amount of particle. The cross-correlation algorithm is used to determine particle's velocity instead of using other devices such as a photodetector. The new instrument allows single particles impacting target planes at different angles with a velocity exceeding 100m/s. An oil calibration test rig has been constructed to verify the proposed methods. The estimation errors of the spatial position and charge amount are both within 5% when the particle is located at the central area of the pipeline and the estimation errors of velocities are within 2%. The impact charging experiments show a special initial charge prior to impact for which no net charge transfer would occur for polymer particles, but the charge would completely transfer for metal particles.

Single Impact Injury of Vertebral Endplates Without Structural Disruption, Initiates Disc Degeneration Through Piezo1 Mediated Inflammation and Metabolism Dysfunction.

In vitro experimental study. To establish an axial impact injury model of intervertebral disc (IVD) and to investigate if a single impact injury without endplate structural disruption could initiate intervertebral disc degeneration (IDD), and what is the roles of Piezo1 in this process. Although IDD process has been confirmed to be associated with structural failures such as endplate fractures, whether a single impact injury of the endplates without structural disruption could initiate IDD remains controversial. Previous studies reported that Piezo1 mediated inflammation participated in the progression of IDD induced by mechanical stretch; however, the roles of Piezo1 in IVD impact injury remain unknown. Rats spinal segments were randomly assigned into Control, Low, and High Impact groups, which were subjected to pure axial impact loading using a custom-made apparatus, and cultured for 14 days. The degenerative process was investigated by using histomorphology, real-time Polymerase Chain Reaction(PCR), western-blot, immunofluorescence, and energy metabolism of IVD cell. The effects of Piezo1 were investigated by using siRNA transfection, real-time PCR, western-blot, and immunofluorescence. The discs in both of the impact groups presented degenerative changes after 14 days, which showed significant up-regulation of Piezo1, NLRP3 inflammasome, the catabolic (MMP-9, MMP-13), and pro-inflammatory gene (IL-1β) expression than that of the control group (P < 0.05), accompanied by significantly increased release of ATP, lactate, nitric oxide (NO), and glucose consumption of IVD cells at first 7 days. Silencing Piezo1 reduced the activation of NLRP3 inflammasome and IL-1β expression in the nucleus pulposus induced by impact injury. It demonstrated that not only fracture of the endplate but also a single impact injury without structural impairment could also initiate IDD, which might be mediated by activation of Piezo1 induced inflammation and abnormal energy metabolism of IVD cells.Level of Evidence: N/A.

A breakage model for particulate solids under impact loading

This paper presents a breakage model of particulate solids under impact loading based on a mechanical approach. Existing breakage models are assessed using the experimental data from single particle impact tests, indicating a more general breakage model is required. Indentation fracture mechanics is used to account for surface damage under dynamic loading. The effect of impact angle is considered in the model, which rationalizes the contributions of both the normal and tangential impact velocity. A unified curve of breakage propensity is constructed using the equivalent velocity under oblique impact based on the experimental data from this study and the literature. This model provides a basis to evaluate breakage propensity of brittle/semi-brittle particles subject to oblique impact and the proposed equivalent velocity has a potential to improve the description of impact energy spectra for milling processes where oblique impact of particle is common and typically ignored.

Parallelized optimization design of bumper systems under multiple low-speed impact loads

Majority of existing design optimization of bumper systems has focused on one single impact loading case in literature, which may not offer proper performance under other loading cases. This study aims to address this issue by developing a multiobjective optimization approach, in which multiple impact loading scenarios are considered to optimize the intrusion and energy absorption of the bumper system. Modeling of real-life impact scenarios is first validated by comparing the numerical results with the experimental data. Based upon the Latin hypercube design (LHD) and Kriging surrogate approaches, energy absorption (EA) and maximum intrusion (MI) are formulated in terms of design variables to consider the structural crashworthiness and repair/maintenance cost, respectively. In order to generate Pareto solution in the multiobjective optimization effectively, the recently developed Kriging Believer based parallelized efficient global optimization (EGO) algorithm is adopted to optimize the bumper system subject to three impact loads, namely the low-speed sled crash, dynamic three-point bending and 40% offset impact, respectively. These different load cases are considered through a weighted average scheme. The optimization results indicate that the Pareto solutions largely depend on the assignment of weight factors to different load cases. In order to generate more reasonable results, the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) database is also used to determine the weighting factors for each loading case. It is found that for the intrusion objective, the design under the multiple impact loads offers an intrusion reduction of 20.27% in the sled crash, 5.84% in the 40% offset impact, in comparison with the baseline design. The intrusion of three-point bending is the same as that of baseline design to compromise other more frequently occurring load cases. For the energy absorption objective, although the design leads to increase in EA by 3.01% in the sled crash and 1.79% in 40%-offset impact, the performance in the three-point bending is actually sacrificed to compromise the other more frequently occurring load cases. The study help gain insights into the design optimization of a bumper system for real-life automotive engineering.