Experimentally Tested Research Articles

Application of power battery under thermal conductive silica gel plate in new energy vehicles

This study aims to improve the performance of automotive battery thermal management systems (BTMS) to achieve more efficient heat dissipation and thus reduce hazards during driving. Firstly, the research parameters and properties of composite thermally conductive silicone materials are introduced. Secondly, the heating principle of the power battery, the structure and working principle of the new energy vehicle battery, and the related thermal management scheme are discussed. Finally, the research results are presented from the experimental test and controller design. In addition, to achieve the research goal, the composite thermally conductive silica gel plate (CSGP) material is studied in detail and parametrically analyzed, and the heating mechanism of the power battery is discussed in depth. The temperature characteristics after adding CSGP are experimentally tested, and the controller of the BTMS of the new energy vehicle is designed, including hardware circuits and software modules. The findings show that the temperature characteristics of the battery module have obvious limitations without CSGP. When the battery module operates at a 4C magnification, the temperature exceeds the safety threshold by 38.4%, with particular potential safety risks. Then, the maximum temperature of the battery module with CSGP can be controlled within 50 °C, and the temperature characteristics are prominently improved. Lastly, the controller of the BTMS is tested, and the results reveal that it has remarkable voltage recovery ability. According to the research results, the performance of automotive BTMS can be significantly improved, and better heat dissipation can be effectively achieved by adding CSGP. This helps reduce the hazards of driving. Moreover, the designed controller performs well in voltage recovery, providing solid theoretical support for further developing the CSGP battery management system.

Randomization Tests for Peer Effects in Group Formation Experiments

Measuring the effect of peers on individuals' outcomes is a challenging problem, in part because individuals often select peers who are similar in both observable and unobservable ways. Group formation experiments avoid this problem by randomly assigning individuals to groups and observing their responses; for example, do first‐year students have better grades when they are randomly assigned roommates who have stronger academic backgrounds? In this paper, we propose randomization‐based permutation tests for group formation experiments, extending classical Fisher Randomization Tests to this setting. The proposed tests are justified by the randomization itself, require relatively few assumptions, and are exact in finite samples. This approach can also complement existing strategies, such as linear‐in‐means models, by using a regression coefficient as the test statistic. We apply the proposed tests to two recent group formation experiments.

Fertility testing of preserved epididymal sperm by microinjection: A model for the rescue and utilization of genetically superior animals.

Epididymal sperm preservation is a simple conservation approach that can help prevent the loss of high genetic quality of farm animals. The chance of loss increases, especially during disease outbreaks or other interruptions to normal reproduction function. This study looked into the ability of preserved ram epididymal sperm to fertilize oocytes. Due to motility becoming an issue following sperm storage for fertilization, the sperm microinjection known as intracytoplasmic sperm injection approach was employed. The study was divided into two parts. First, involved the preservation of epididymal sperm at 5°C for 12 days. During preservation, sperm quality parameters namely motility, viability, intact membrane, acrosome, and Deoxyribonucleic acid (DNA) are evaluated every three days. For the fertility test in the second experiment, matured oocytes were injected with immotile sperm discovered in the last days of preservation. The presence of pronucleus development following in vitro culture is used as an indicator of sperm's ability to activate and fertilize oocytes. All sperm quality parameters significantly (p < 0.05) declined during preservation time. On day 12, motility was discovered to be 0%, but viable sperm, sperm with intact membrane, acrosome, and DNA remained at 41.86% ± 9.30%, 31.18% ± 5.15%, 21.88% ± 1.93%, and 33.35% ± 8.74%, respectively. On the fertility test, we inject immotile sperm from day 12 of preservation, which has the lowest motility found, into matured oocytes. Those sperms are able to activate (52.05% ± 7.15%) and fertilize (31.37% ± 1.75%) the injected oocytes, but their fertilizing ability is significantly lower (p < 0.05) when compared to the sperm derived from the ejaculate. In this study, simple preservation of epididymal sperm reduces all sperm quality criteria, particularly motility. Using the microinjection approach preserved sperm which had no motility, still demonstrated its ability to activate and fertilize the oocytes. According to that, this study provides potential approaches and tools for using genetically superior animals that have lost their ability to execute regular fertilization, and also prolong reproduction function.

Supervisory control of reactive power in wind farms with doubly fed induction generator-based wind turbines for voltage regulation and power losses reduction

This paper proposes a strategy based on the secondary voltage control (SVC) and the use of grid codes recommended by the system operator to determine the reactive power reference value between a wind farm (WF) with doubly-fed induction generator (DFIG) and the electrical grid. The proposed strategy seeks to determine the reactive power reference value required of WF during normal operating and grid faults. When the voltage deviation is within the normal range, the proposed strategy maintains a unity power factor (UPF). If the voltage deviation exceeds the normal range, it provides reactive power compensation to ensure voltage stability. To achieve this objective, the proposed strategy is compared with the SVC. This strategy can reduce the size of potential compensation devices, such as static synchronous compensators, to be used to improve the WF response, if needed. The participation of the grid converter side (GSC) in the reactive power control allows the DFIG to reduce power losses and increases the life of the converters, especially the rotor converter side (RSC). The strategy proposed in this work is implemented on Matlab/Simulink using the S-Function builder to evaluate their performance, which facilitates its integration into real control boards and testing in real experiments in the future.

Energy management for proton exchange membrane fuel cell-lithium battery hybrid power systems based on real-time prediction and optimization under multimodal information

As an emerging power source for new energy vehicles, the proton exchange membrane fuel cell-lithium battery hybrid power system still faces challenges such as difficulty in remaining life prediction and unreasonable energy allocation management. This study investigates how electrochemical surface area degradation and carbon corrosion in the catalyst layer affect the proton exchange membrane fuel cell output power. An integrated assessment system combining electrochemical surface area degradation and carbon corrosion, which could effectively evaluate degradation in the proton exchange membrane fuel cell degradation is proposed. To assess the lifespan of proton exchange membrane fuel cells, the electrochemical surface area degradation and carbon corrosion are utilized as key indicators, which in turn lead to the development of a semi-empirical model. To solve the problem of energy allocation management, this paper proposes a predictive-feedback optimization method that combines data-driven and model-driven approaches. The method includes a hybrid prediction model of a long short-term memory-convolutional neural network, an improved rapid optimization strategy of grey wolf optimizer-particle swarm optimization, and an attention-enhanced fuzzy neural network controller. The inference capability of the convolutional neural network is utilized to correct the larger prediction error of long short-term memory during short-term drastic changes, realizing the maximization of energy utilization efficiency, minimal hydrogen consumption, minimization of operation cost, and optimization objectives for information containing a wide time horizon. Tests of experiments show that the implementation of this control scheme effectively postponed the deterioration of the proton exchange membrane fuel cell-lithium battery hybrid power system, resulting in an extended lifespan.

Elastic Behavior of Transversely Isotropic Cylindrical Rock Samples under Uniaxial Compression Considering Ideal and Frictional Boundary Conditions

Conceptualizing sophisticated measurement set-ups as well as testing and evaluation procedures for laboratory experiments on anisotropic rocks requires a basic understanding of the potential specimen behavior. The focus of the present work was therefore to investigate the influence of different transversely isotropic parameters and their ratios on the elastic behavior of cylindrical rock samples in uniaxial compression tests. Parameter sets corresponding to soft anisotropic rocks were chosen based on naturally observed ranges for the five elastic transversely isotropic constants. Analytical results for the radial and vertical strain distributions around the sample circumference and a comparison with finite element simulations are presented. Further, the effect of interface friction between samples and loading platens was analyzed within the numerical models. The results suggest that radial strains around cylindrical anisotropic samples are rarely uniform except for specific combinations of parameters and isotropy plane inclinations. The effect of interface friction was found to have a clear influence on the developing elastic stress and strain distributions for samples with inclined isotropy planes. Nevertheless, no significant influence of frictional boundary conditions on the back-calibrated values of the elastic parameters could be identified, suggesting that friction-reducing measures in uniaxial compression tests on transversely isotropic samples with predominantly linear behavior are not required.

Statistical inference of a step-stress model with competing risks under time censoring for alpha power exponential distribution

Accelerated life testing in a reliability experiment allows test units to be under more stress than normal (expected). Step-stress tests are a subset of accelerated life tests that raise the stress levels at specific predetermined time periods to gather data on lifetime parameters more quickly than they would under normal operating settings. Additionally, there are frequently a number of risk factors connected to the root cause of a test unit failure (mechanical, electrical, etc.). In this article, we discuss the statistical inference of a step-stress model in the presence of time censoring assuming independent alpha power exponential distribution. The point estimates of the unknown scale and shape parameters of the various causes are determined using the maximum likelihood technique under the assumption of cumulative damage. We also go through creating confidence intervals for the parameters using asymptotic distributions and the parametric bootstrap approach. Extensive Monte Carlo simulations are used to evaluate the accuracy of the estimates and the performance of the confidence intervals, and finally, an example is used to explain the methods of inference presented here.

Ultra-stable control near the EP in non-Hermitian systems and high-precision angular rate sensing applications.

In non-Hermitian systems, enhancing sensitivity under exceptional point (EP) conditions offers an ideal solution for reconciling the trade-off between sensitivity and size constraints in sensing applications. However, practical application is limited by undesired sensitivity to external fluctuations, noise, and errors in signal amplification synchronization. This paper presents a precisely controlled EP tracking and detection system (EPTDS) that achieves long-term rapid tracking and locking near the EP by constructing a second-order non-Hermitian optical sensing unit, employing an optical power adaptive control method, and utilizing a combinatorial demodulation-based dual-loop cascaded control (CDCC) technique to selectively suppress traditional noise at different frequencies. The system locking time is 10 ms, and in room temperature conditions, the output frequency error over 1 hour is reduced by more than 30 times compared to before locking. To assess its sensing capabilities, the EPTDS undergoes testing in a rotational experiment based on the Sagnac effect, with the output bias instability based on Allan deviation measured at 0.036 °/h. This is the best result for EP-enhanced angular rate sensing that we are aware of that has been reported. The EPTDS method can be extended to various sensing fields, providing a new path for transitioning non-Hermitian sensing from the laboratory to practical applications.

Measuring trust with the Wayfinding Task: Implementing a novel task in immersive virtual reality and desktop setups across remote and in-person test environments.

Trust is a key feature of social relationships. Common measures of trust, questionnaires and economic games, lack ecological validity. Hence, we sought to introduce an immersive, virtual reality (VR) measure for the behavioral assessment of trust across remote and in-person settings, building on the maze task of Hale et al. (2018). Our 'Wayfinding Task' consists of an interconnected urban environment for participants to navigate on the advice of two characters of differing trustworthiness. We present four studies implementing the Wayfinding Task in remote and in-person testing environments and comparing performance across head-mounted display (HMD)-based VR and desktop setups. In each study, the trustworthiness of two virtual characters was manipulated, through either a fact sheet providing trustworthiness information, or a behavior-based trustworthiness manipulation task termed the Door Game, based on Van der Biest et al., 2020. Participants then completed the Wayfinding Task. Overall, we found that participant behavior in the Wayfinding Task reflected the relative trustworthiness of the two characters; in particular, the trustworthy character was approached more often for advice, reflecting data from our Door Game. We found mostly null results for our novel outcome measure, interpersonal distance. Remote testing successfully achieved these effects. While HMD-based VR and desktop setups both showed these effects, there was a stronger effect of trustworthiness in the HMD VR version of the task. These results have implications for the measurement of trust in behavioral settings and the use of remote and VR-based testing in social experiments.

Assessment of critical parameters affecting the behaviour of bearing reinforced concrete walls under fire exposure

PurposeThis research paper aims to investigate reinforced concrete (RC) walls' behaviour under fire and identify the thermal and mechanical factors that affect their performance.Design/methodology/approachA three-dimensional (3D) finite element (FE) model is developed to predict the response of RC walls under fire and is validated through experimental tests on RC wall specimens subjected to fire conditions. The numerical model incorporates temperature-dependent properties of the constituent materials. Moreover, the validated model was used in a parametric study to inspect the effect of the fire scenario, reinforcement concrete cover, reinforcement ratio and configuration, and wall thickness on the thermal and structural behaviour of the walls subjected to fire.FindingsThe developed 3D FE model successfully predicted the response of experimentally tested RC walls under fire conditions. Results showed that the fire resistance of the walls was highly compromised under hydrocarbon fire. In addition, the minimum wall thickness specified by EC2 may not be sufficient to achieve the desired fire resistance under considered fire scenarios.Originality/valueThere is limited research on the performance of RC walls exposed to fire scenarios. The study contributed to the current state-of-the-art research on the behaviour of RC walls of different concrete types exposed to fire loading, and it also identified the factors affecting the fire resistance of RC walls. This guides the consideration and optimisation of design parameters to improve RC walls performance in the event of a fire.

Developing A Solid Termite Bait Matrix and Conducting Efficacy Trials Under Lab and Semi Field Conditions

The study on development of solid termite bait matrix and its efficacy against the Heterotermes indicola was performed in Peshawar, during 2023. The study was performed with completely randomized design (CRD) with different treatments i.e., developed bait, patent bait, popular wood and blotting paper. Each treatment was replicated three times. The laboratory experiment consisted of no-choice, free choice and aggregation test. While the semi-field experiment consisted of free choice test. During the no-choice test of the laboratory experiment, H. indicola showed a consumption rate of 6.29% for the popular wood and developed bait. However, in the blotting paper treatment, the termites consumed only 2.81%. In terms of choice test conducted in the lab, the popular wood exhibited the highest weight consumption percentage of 2.87%, while the patent bait displayed the lowest weight consumption percentage of 2.25%. Under the choice test maximum number of termites were attracted towards popular wood (77.00 Number of termites) while minimum number of termites were attracted towards patent bait (54.66 Number of termites). Whereas, in aggregation test, of the lab experiment, maximum number of termites were also aggregated towards popular wood (37.77 Number of termites) while minimum termites were aggregated for patent bait (25.22 Number of termites). In the case of free choice under semi-field conditions, the highest number of termites were observed on popular wood i.e., 380.00 followed by the developed bait, which recorded 293.50 termites. On the other hand, the lowest number of termites were recorded on the patent bait i.e., 231.50. Similarly, when considering the maximum consumed weight in percentage, popular wood exhibited the highest value at 16.24%, closely followed by the developed bait at 15.67% while the patent bait displayed minimum consumed weight percentage of 12.89%. In overall experiments it is concluded that among all the tested treatments, termites mostly consumed popular wood and developed bait. Since the developed bait showed promising results in attracting termites, it is recommended to continue refining its formulation. Conduct additional research to identify the key components or additives that enhance its attractiveness and consumption by termites. This optimization process can help maximize the effectiveness of the bait as a termite control strategy. Adding more popular wood saw dust in the bait may achieve more significant and desired results and can also prove to be cost efficient rather than adding more cellulosic material.

Towards composite suspension control arm: Conceptual design, structural analysis, laminate optimization, manufacturing, and experimental testing

The automotive industry needs composite materials to decrease the weight of new-generation vehicles whilst increasing their strength. In this study, one of the critical (load bearing) components of automobiles, i.e., the suspension control arm made of steel, is fully redesigned for its suitable manufacturing using composite materials. To this end, innovative mechanical simulation methods are developed and coupled to perform the design, analysis, and optimization of the automotive suspension control arm. The main design/optimization criteria are set to reduce no less than 75% weight of the metal control arm and increase its safety by at least 60% by using composite materials and a new geometry suitable for mass production. To predict the deformation-stress state of the control arm, a four-node quadrilateral shell element is implemented based on the kinematics of refined zigzag theory (RZT). Once verified numerically, the computer implementation of the RZT is combined with the optimization algorithm to achieve the optimum laminate stacking sequence of the control arm. Accordingly, prototypes of the composite control arms with optimum lamination plans are manufactured and then experimentally tested under the loading and constraint conditions defined at the conceptual design stage. The numerical and full-scale experimental results are compared, and the RZT models are comprehensively validated. Hence, the advantages of the overarching design-analysis-optimization strategy presented herein are revealed for redesigning and manufacturing automobile parts from composite materials.

Crowdsourcing as a tool for creating effective nudges: An example for financial oversubscription.

Creating effective nudges, or interventions that encourage people to make choices that increase their welfare, is difficult to execute well. Recent work on megastudies, massive field experiments that test many interventions simultaneously, reveals that nudge effectiveness both varies widely and is difficult for experts to predict. We propose an Iterative Crowdsourcing Procedure, which uses insights from members of the target population to generate and preselect nudges prior to testing them in a field experiment. This technique can supplement existing methods or stand alone as a way to generate conditions for testing in a high-quality field experiment. We test the effectiveness of this method in addressing a challenge to effective financial management: consumer oversubscription. We first document that people have more subscriptions than they think they have and that enhancing subscription awareness makes people want to cancel some subscriptions. We then use our crowdsourcing procedure to motivate people toward subscription awareness in a field experiment (N = 4,412,113) with a large bank. We find that the crowdsourced nudges outperform those generated by the bank, demonstrating that the Iterative Crowdsourcing Procedure is a useful way to generate effective nudges.

SHEAR BEHAVIOUR OF REINFORCED-CONCRETE BEAMS INCORPORATING IRON FILINGS AS SAND REPLACEMENT

This study examined the influence of partial sand replacement with iron filings on the mechanical and physical characteristics of concrete, as well as conducted experimental tests of the shear behaviour of reinforced-concrete beams. Four replacement rates were used in this study, i.e., 5 %, 10 %, 20 %, and 30 % with a reference mixture containing no iron filings. At ages 7, 14, and 28 days, mechanical property tests (slump, density, ultrasonic pulse velocity, compressive strength, and splitting strength tests) were conducted. In addition, the shear behaviour of five reinforced-concrete beams with the same replacement rates (0 %, 5 %, 10 %, 20 %, and 30 %) were experimentally tested. Tests were conducted to determine the ultimate load failure, final deflection, energy absorption, stiffness, ductility index, compressive stress, and crack formations. According to the results, the correlation between the slump test and iron filings is positive; however, that for absorption is negative. With a higher percentage of iron-filing replacement, the density and ultrasonic pulse velocity increased. For specimens with 30,00 % iron filings, the densities, pulse velocities, and slumps were raised by 6,27 %, 2,44 %, and 58,33 %, respectively, compared to the reference specimens, whereas the absorption rate decreased by 20,00 %. Having 20,00 % iron filings produced the maximum compressive and splitting strengths of 28,00 %, which was 4,60 % higher than the reference mixture, whereas 30,00 % iron filings produced the highest flexural strength, which was 9,50 % higher than the reference mix. The findings of beam testing revealed that increasing the iron-filing content in concrete beams increased the final failure load, final deflection, ductility index, and energy absorption by 6,70 %, 10,29 %, 11,30 %, and 35,00 %, respectively. The initial and secant stiffnesses decreased at rates of 12,60 % and 3,10 %, respectively.

Development of an Airbag Geometry Specific for Autonomous Vehicles

Airbags are important safety devices in modern vehicles. However, their effectiveness is linked to the occupants being seated in standard positions. Although autonomous vehicles are less accident-prone, they are also equipped with airbags, similar to any other vehicle. Additionally, autonomous vehicles allow for occupants seated in non-standard positions, so in the case of a collision, the airbags’ effectiveness decreases. In this work, an airbag design suitable for both assisted and autonomous driving conditions is proposed, the driver’s airbag being the object of interest. Airbag geometry, threads, seam strength, and seam geometries were selected following Design of Experiments (DoE) methodologies and a series of experimental tests. Moreover, an adaptive system based on sewn tethers allows the airbag to adapt to the driving mode, which is proposed and validated. Finally, all the findings were experimentally tested on two different geometries. The results were satisfactory as the deployed airbag shape and dimensions were as expected, indicating that this airbag design is capable of protecting the driver of a vehicle capable of autonomous driving.

Experimental Validation of a High-Speed Tracked Vehicle Powertrain Simulation Model

Abstract High-speed tracked vehicles have complex powertrains that, in addition to power transfer and transformation, also perform the functions of vehicle steering and braking systems, as well as power supply system for various subsystems on the vehicle. Analyzing the power balance of a tracked vehicle, especially in specific moving scenarios such as the turning process, is of great importance for understanding the power requirements and workload of the powertrain components and their optimization. A simulation model was developed, based on the construction parameters of an experimentally tested high-speed tracked vehicle to reduce the time and material resources required for experimental testing. Both the simulation and experimental tests were conducted using the same input parameters and driving conditions for different vehicle turning scenarios. Simulation and experimental test results are compared to verify the accuracy of the simulation model. The analysis of the obtained results shows that the average value of the relative rpm error is about 5%, the average value of the relative torque error is about 7%, while the average value of the relative power error is about 6.5%.

An experimental test of the Big-Fish-Little-Pond Effect using an immersive virtual reality classroom

Academic self-concept plays a central role in successful learning and is substantially shaped by social comparisons. Research on the so-called Big-Fish-Little-Pond Effect (BFLPE) has yielded a highly robust and generalizable pattern of negative effects of higher class/school average achievement on students’ self-concept when controlling for individual achievement. However, most BFLPE studies have not provided information about the causes behind or the mechanisms underlying the proposed effects. To address this, we used a fully immersive virtual reality (IVR) classroom to experimentally test the extent to which students recognized performance-related classroom behavior as implicit social comparison information and how these perceptions explained differences in students’ self-concepts. Participants (N = 381 sixth-grade students) experienced an authentic yet standardized IVR teaching situation with virtual classmates who exhibited different performance levels (operationalized as 20% vs. 35% vs. 65% vs. 80% of classmates raising their hands). Hand-raising behavior had a significant positive effect on students’ perceptions of the class’ performance level (d20% vs. 65% = 0.60; d20% vs. 80% = 1.24). In line with the BFLPE, results showed a negative effect of higher performing classmates on students’ situational self-concept (d20% vs. 80% = 0.30). Students’ perceptions of the class’ performance level fully explained the effect of classmates’ hand-raising behavior on students’ situational self-concept. The study’s experimental approach provided new insights into the emergence of social comparison effects in the classroom, highlighting the major role of students’ perceptions of their classmates’ performance-related behavior, and moreover demonstrated the general potential of using IVR in classroom research.

Stiffness of Experimentally Tested Horizontally Loaded Walls and Timber-Framed Modular Building.

This paper presents an overview of representative up-to-date research and the authors' own experimental results from tests of wall elements and a horizontally loaded timber-framed modular building. The research has been conducted in connection with the development of timber-based structures in recent years. In the present research, wall elements and modules of timber-frame construction with life-size dimensions were used. So far, these types of structures have mainly been tested in laboratories-especially with regard to anchoring and cyclic loading. An experimental testing was carried out on a natural scale in two stages based on the standard procedure described in EN 594. In the first stage, wall panels were tested. In the second stage, tests were carried out on a complete four-storey building. Dowel fasteners were used to fix the sheathing to the load-bearing wall structures. Additionally, the sheathing was glued to the timber frame of the walls. The same type of wall element was used for the construction of the tested building. Horizontal loads were applied at the height of the top of the walls in both stages. The building loads were applied in a direction perpendicular to the longitudinal axis of the modules. Based on test data, the stiffnesses of the wall panels and the whole building were derived, as well as the type of interaction between the modules and the influence of the walls on the spatial work of the building. On the basis of the conducted studies, both the stiffness of the walls in different configurations and the stiffness of the complete building were determined, as well as the nature of the interaction of neighbouring modules and the influence of wall connections on the 3D working of the building. The results show that the stiffness of the building in the horizontal plane in the direction of the applied load is almost twice as high as the sum of the stiffnesses of the building walls in the same direction.

Digitalisation as a Prerequisite for the Groundswell Concept Encouraging the Optimisation of Investments in Online Advertising Using an Audit Approach

In an environment of hypercompetition, Industry 4.0 and the impact of the social trend called groundswell on corporate communication mediated through social media, online advertising is critical to enterprise marketing. Moreover, the COVID-19 pandemic has accelerated the transformation from classical advertising to digital. The Controlling/Audit approach could serve as a tool for optimising online advertising performance. The paper analyses a sample of online advertisements (n=248,812) and the finding of this research points to possible significant improvement in CPT (Cost per thousand) ratio and enhanced efficiency of enterprise marketing strategies. Based on the research findings, three linear regression models were developed for improving investment in online advertising. These models were used to set up a controlling/audit approach that was experimentally tested in selected enterprises. Experimental testing proved that Controlling/Audit improved the efficiency of online advertising, in some cases, by over 50% in terms of CPT. &#x0D; &#x0D; Received: 24 June 2023 / Accepted: 23 August 2023 / Published: 5 September 2023

Buckling and fracture analysis of thick and long composite cylinders with cutouts under axial Compression: An experimental and numerical campaign

This article reports on the manufacturing, experimental testing, and finite element analysis of very thick and long carbon-fiber-reinforced polymers (CFRP) tubes under uniaxial compression (radius-to-thickness ratio ∼ 10 and length-to-radius ratio ∼ 21). Herein, long and hollow axisymmetric composite cylinders were produced through bladder molding. The CFRP tubes have two oppositely located cutouts in the middle of the structures. Three test specimens with different cutout diameters (5, 10, and 15 mm) were experimentally tested until failure. The experimental testing campaign was supported by digital image correlation, acoustic emission, and infrared thermographic measurements to investigate the damage propagation and failure analysis. The CFRP tubes failed at the cutout location due to fiber fracture. Linear static and geometrically non-linear analyses were performed using ABAQUS to analyze the CFPR tubes under axial compression. In general, numerical and experimental results are in good agreement if the maximum stress or Hashin criteria are applied.