Mixed Stage Research Articles

Upgraded one-dimensional code for the design of a micro gas turbine mixed flow compressor stage with various crossover diffuser configurations

Abstract Micro Gas Turbine (MGT) designers often have the need for a design tool, capable of rapidly providing feasible design options. The upgrade of such an existing MATLAB® based mixed flow compressor design application (1D App) is discussed. In MGT engines, diffuser design largely influences the compressor stage performance. Crossover diffusers provide superior efficiency and pressure ratio performance compared to legacy type diffusers, albeit at the expense of operating range. The reduced operating range attributed to single vane crossover diffusers can be alleviated by splitter vane, tandem vane, and combined configurations. Therefore, the 1D App is updated to allow the user the ability to design these additional crossover diffuser configurations. Performance results are verified using Numeca/FINE™ Turbo CFD software. It is shown that the upgraded 1D App provides predicted performance results within 1 % of CFD results for both total-to-total efficiency and pressure ratio.

Genetic and environmental contributions to the development of soft tissue facial profile: a twin study.

This study aimed to determine the relative contribution of genetic and environmental factors in the phenotypic variation of the soft tissue facial profile during the mixed dentition and the permanent dentition stages. In this retrospective cohort study, standardized facial profile photographs of 139 twin pairs (55 monozygotic and 84 dizygotic) were obtained from archival records at the Adelaide Dental School. Photographic analysis used 12 angular and 14 linear facial profile measurements from the mixed dentition (7-11 years) to the permanent dentition (12-17 years) stages. A genetic analysis was performed using a univariate structural equation model adhering to the normal assumptions of a twin model. In the mixed dentition stage, the additive genetic (A) and unique environment (E) model, AE model, was the most parsimonious in explaining the observed phenotypic variance for all 26 facial traits with the narrow-sense heritability estimates ranging between 0.38 and 0.79. In the permanent dentition, the AE model was the most parsimonious for 20 out of 26 traits, however, the variance of six traits, particularly those in the lower third of the face, was best explained by the shared environmental and unique environmental factors. This study exclusively included twins of European ancestry. The soft tissue facial profile demonstrated dynamic genetic and environmental influences with a greater additive genetic influence during the mixed dentition and the early stages of the permanent dentition. However, there was evidence of increasing environmental influence in the lower third of the face during the early stages of the permanent dentition.

Environmental Driving Mechanism and Response of Soil’s Fungal Functional Structure to Near-Naturalization in a Warm Temperate Plantation

In this study, the near-naturalization process of Pinus tabulaeformis plantations in Baxianshan National Nature Reserve was divided into three stages depending on the proportion of P. tabulaeformis present, resulting in the following categories: the P. tabulaeformis forest stage, the mixed forest stage, and the near-natural forest stage. Natural secondary forests were selected as a control. We assessed alterations in the soil’s fungal functional structures from three aspects: functional mode, vegetative mode, and growth mode, and their responses to vegetation and soil factors were also explored. The results showed that ectomycorrhizal, saprophytic, and plant pathogen types were dominant in the functional mode, and plant pathogens were most abundant in the P. tabulaeformis forest stage. Meanwhile, ectomycorrhizal fungi were the least abundant in the near-natural forest stage. In the vegetative mode, saprophytic, pathophysiological, and symbiotic types were dominant, and pathophysiological types were the most abundant in the P. tabulaeformis forest stage. In the growth mode, microfungi dominated, and the abundance of clavarioid decreased with near-naturalization. The degree of variation in functional structure in the three dimensions increased with near-naturalization, but the structure of natural secondary forests converged. The species composition of tree layer obviously affected the abundance and functional structure of fungi in the three modes, among which Quercus mongolia and Carpinus hornbeam were the most significant. The soil’s pH and nitrate content significantly affected the structure of the functional mode, and the soil’s dry matter content and C/N ratio significantly affected the structure of the vegetative mode. In this study, we explored the interaction between the plant community and soil ecological system during the near-naturalization process of plantations in terms of soil fungi functions, further clarifying the role of soil functions in the succession of plant communities and providing a new perspective on the in-depth exploration of ecosystem interactions during the succession of plantations.

High prevalence of adult and nonadult scurvy in an early agricultural transition site from Mainland Southeast Asia was associated with decreased survivorship.

The osteological paradox recognizes that the presence of lesions is not always directly related with increased mortality. When combined with the clinical, historical, and epidemiological literature on scurvy, survivorship analysis, a form of statistical analysis to assess the relationship between the presence of diseases in the archeological record and survival, helps determine the overall burden of the disease both in terms of morbidity and mortality. This article explores the relationship between scurvy and survivorship in 26 adults from Man Bac, a Neolithic site from northern Vietnam together with prepublished evidence of scurvy in the nonadult population (n = 44). Diagnosis of scurvy included differential diagnosis combined with the Snoddy, A. M. E., Buckley, H. R., Elliott, G. E., Standen, V. G., Arriaza, B. T., & Halcrow, S. E. (2018). Macroscopic features of scurvy in human skeletal remains: A literature synthesis and diagnostic guide. American Journal of Physical Anthropology, 167(4), 876-895. https://doi.org/10.1002/ajpa.23699 threshold criteria and the Brickley, M. B., & Morgan, B. (2023). Assessing diagnostic certainty for scurvy and rickets in human skeletal remains. American Journal of Biological Anthropology, 181, 637-645 diagnostic certainty approaches. Kaplan-Meier survival curves were produced to assess the relationship between the presence of probable scurvy and age-at-death. The prevalence of probable scurvy in adults (35%) was considerably lower than reported for the nonadults (80%). Almost all lesions observed in the adults were in a mixed stage of healing. Kaplan-Meier analysis demonstrated no difference in survivorship between infants and children (<15 years) with or without probable scurvy, whereas a meaningful difference was observed for the adults and adolescents (15+ years). The findings demonstrate that scurvy considerably decreased survivorship to older age categories. The degree of lesion remodeling, however, indicates that scurvy was not necessarily the direct cause of death but contributed to an overall disease burden that was ultimately fatal.

Enacting Human-Robot Encounters with Theater Professionals on a Mixed Reality Stage

In this paper, we report on methodological insights gained from a workshop in which we collaborated with theater professionals to enact situated encounters between humans and robots on a mixed reality stage combining VR with real-life interaction. We deployed the skills of theater professionals to investigate the behaviors of humans encountering robots to speculate about the kind of interactions that may result from encountering robots in supermarket settings. The mixed reality stage made it possible to adapt the robot’s morphology quickly, as well as its movement and perceptual capacities, to investigate how this together co-determines possibilities for interaction. This setup allowed us to follow the interactions simultaneously from different perspectives, including the robot’s, which provided the basis for a collective phenomenological analysis of the interactions. Our work contributes to approaches to HRI that do not work towards identifying communicative behaviors that can be universally applied but instead work towards insights that can be used to develop HRI that is emergent, and situation- and robot-specific. Furthermore, it supports a more-than-human-design approach that takes the fundamental differences between humans and robots as a starting point for the creative development of new kinds of communication and interaction.

Assessing the Efficacy of Early versus Late Orthodontic Intervention in the Management of Class II Malocclusion: A Comparative Analysis

ABSTRACT Background: Class II malocclusion is a common orthodontic issue characterized by the excessive protrusion of the upper teeth relative to the lower teeth. Early intervention during mixed dentition has been advocated to guide skeletal growth and potentially reduce the severity of malocclusion. Materials and Methods: A comparative analysis was conducted to evaluate the efficacy of early (before the pubertal growth spurt) versus late (after the pubertal growth spurt) orthodontic intervention in managing Class II malocclusion. A cohort of 100 patients diagnosed with Class II malocclusion was divided into two groups: early intervention group (n = 50) and late intervention group (n = 50). Treatment outcomes including changes in overjet, molar relationship, and cephalometric measurements were assessed before and after orthodontic treatment. Results: In the early intervention group, the mean reduction in overjet was 5.2 mm (SD = 1.3), while in the late intervention group, it was 3.8 mm (SD = 1.6). The improvement in molar relationship was greater in the early intervention group (mean change = 4.5 mm, SD = 1.1) compared to the late intervention group (mean change = 3.1 mm, SD = 1.4). Cephalometric analysis revealed significant differences in skeletal and dental parameters between the two groups, with greater improvements observed in the early intervention group. Conclusion: Early orthodontic intervention shows superior efficacy in managing Class II malocclusion compared to late intervention. Early treatment leads to greater reductions in overjet, improvements in molar relationship, and favorable changes in skeletal and dental parameters. These findings underscore the importance of timely orthodontic intervention, particularly during the mixed dentition stage, for optimal management of Class II malocclusion.

Drivers of β-diversity and its component-dependence along the natural restoration in an extremely heterogeneous forest ecosystem

β-diversity usually refers to species turnover along a gradient or changes in species diversity between communities. It is a key concept in understanding the mechanisms of biodiversity pattern formation. However, the component dependence and the driving factors of β-diversity during natural restoration remain unclear. In this study, a series of forest dynamic plots (FDPs) were established through the natural restoration stages in degraded karst forests, including the shrub-canopy mixed forest stage (SC), the secondary-growth forest stage (SG), and the old-growth forest stage (OG). After comparing species composition during natural restoration and its dependence on species turnover and nestedness, it was found that natural restoration significantly influenced the species composition by altering the species turnover in degraded karst forests rather than the nestedness. The contribution of turnover to β-diversity gradually increased, while the contribution of nestedness decreases gradually. Furthermore, the PER-SIMPER method was used to quantify the first-order assembly process that drives variations in species composition during restoration stages. To identify the factors influencing β-diversity, both variation partitioning analysis and a random forest model were employed. The results suggested that differences in species compositions across restoration stages were mainly driven by stochastic processes, and the deterministic processes were strengthened during the natural restoration. In addition, topographic factors contributed more to β-diversity than soil nutrient factors. This study highlighted changes in component dependence of degraded karst forests during natural restoration and emphasized the importance of a more comprehensive framework in assessing the restoration of degraded forest ecosystems. More attention should be paid to topographic structure in understanding biodiversity patterns, especially in highly heterogeneous forest ecosystems.

Vertical and transverse treatment effects of Invisalign First system compared to Hyrax maxillary expanders with fixed appliances in mixed dentition patients.

To compare vertical and transverse changes in mixed dentition patients treated with the Invisalign First System (IFS) to those treated with a banded hyrax expander with fixed appliances (Hyrax) and control groups, and to assess the efficiency rate of dental arch expansion with IFS. The study included 80 mixed dentition patients, with 40 in each group (IFS and Hyrax) and 40 controls from the American Association of Orthodontists Foundation Craniofacial Growth Legacy Collection. Skeletal and dental vertical dimension changes and arch width changes between pretreatment (T1) and posttreatment (T2) were evaluated. Age at T1, time interval (T1-T2), sex, and Angle class did not significantly differ among the groups. Mandibular plane angle changes showed a similar reduction for the control and IFS groups, with no changes in the Hyrax group. However, the differences among the three groups did not reach statistical significance (P = .06). The Hyrax group showed significantly greater expansion in maxillary intermolar width compared to the IFS group, 4.4 vs 2.5 mm, respectively. The efficiency of maxillary expansion using IFS ranged from 52.3% to 76.87%. During the mixed dentition stage, no significant changes occurred in vertical dimensions among the control, Hyrax, and IFS groups. Although there was a trend suggesting a greater reduction in mandibular plane angle in the IFS group compared to the Hyrax group, this may not be clinically significant given the less than 1° difference. IFS can be a viable option for addressing mild arch width deficiencies, with a predictable increase in intermolar width of approximately 2.5 mm.

Radiological features and treatment of erupting maxillary canines in relation to the occurrence of dental developmental abnormalities.

This study aimed to investigate the radiological features of the permanent canines and the treatment carried out to ensure their eruption relative to certain features involved in Dental Anomaly Patterns (DAP). The cross-sectional part of this retrospective register--based study focused on 1,315 dental panoramic tomographs (DPTs) of children aged 8.5-10.5 years, while the longitudinal part involved information on the treatment provided for 1,269 canines after the DPTs and on their eruption into the oral cavity. The canines of the DAP children more often showed evidence of early treatment (p = 0.014), with girls having more frequently interceptive treatment (p = 0.004) and boys early headgear (p = 0.022). Delayed dental age was associated with early treatment (OR 3.29, 95% CI 1.08-9.99). Either no or clear overlapping of a canine with the lateral incisor occurred more often in the DAP children, whereas canine inclination did not differ between the groups. The root development stage of the canine was more often either beginning or well advanced in the DAP children. The children with dental developmental abnormalities more often showed evidence of early treatment for the canines. Monitoring of the erupting canines after the first mixed stage is important to enable timely early treatment.

Catch them early and treat them Young: Early Orthodontic treatment in developing Class II cases, a review and case report

Developing Class II malocclusion is relatively a common presentation in the mixed dentition stage. Early interception and treatment at an appropriate age can avoid a host of problems that may complicate future orthodontic treatment. This article highlights a case report and gives an insight regarding the topic.

The effect of a tandem vane crossover diffuser configuration on the performance of a MGT mixed flow compressor

Due to the inherent geometric restrictions of a micro gas turbine (MGT) mixed flow compressor design, diffuser design has a major impact on compressor performance and operating range. Vaned diffusers are often preferred to vaneless diffusers in MGT compressor designs due to better efficiency and pressure recovery, albeit at the expense of operating range. A numeric investigation of the effect of a tandem vane crossover diffuser configuration on the performance and operating range of a MGT mixed flow compressor stage is presented. Three baseline test compressors, covering a wide range of design speeds, mass flow rates and meridional exit angles, are designed with a single vane crossover diffuser. For each of the three baseline compressors, the crossover diffuser design is modified to feature various tandem vane configurations. The tangential shift of the second vane row relative to the first row is evaluated. Additionally, relative first and second vane row lengths are evaluated. The performance (efficiency and pressure ratio) and operating range of the modified diffuser configurations are compared to the baseline configurations. It is shown that a 75% second vane row tangential shift configuration displays the best overall performance, regardless of the relative vane length. It is further shown that an appropriate vane length depends on the design requirement.

An epidemiological study on early orthodontic treatment need among eastern Saudi Arabian children in the mixed dentition stage.

Estimation of early orthodontic treatment need among children is essential for planning orthodontic interventions in the mixed dentition stages thereby reducing the burden in a publicly funded healthcare system. The present study aimed to assess the early orthodontic treatment need among children with mixed dentition in the Eastern Saudi Arabia. A descriptive cross-sectional study was conducted among Saudi children visiting the outpatient clinics in a University dental setting, and data were collected based on Index for preventive and interceptive orthodontic need (IPION). Descriptive statistics, chi-square test and Fisher's exact test were used for data analysis with statistical significance set at p < 0.05. The category of 'no treatment need' accounted for 11.3% while 'moderate treatment need' and 'definite treatment need' categories accounted for 29.3% and 59.4% respectively. There was no statistical difference between males and females in the distribution of the three categories of treatment need (p = 0.513). This study demonstrated a very high need for early orthodontic treatment among Saudi children in the mixed dentition stage. Emphasis should be placed on increased awareness and benefits of seeking early orthodontic treatment involving preventive and interceptive procedures in the mixed dentition.

The Impact of Early Orthodontic Intervention on Dental and Skeletal Development in Children with Mixed Dentition.

The mixed dentition stage in children is a critical period for orthodontic assessment and intervention. This study investigates the effects of interceptive orthodontics on dental and skeletal development in children with mixed dentition, aiming to evaluate the potential benefits of early orthodontic treatment. A retrospective analysis was conducted on a cohort of 150 children with mixed dentition (aged 7-11 years), who received interceptive orthodontic treatment. Dental and skeletal records, including cephalometric radiographs and dental cast models, were collected before and after treatment. A control group of 150 untreated children with mixed dentition was also assessed for comparison. Various dental and skeletal parameters, such as dental alignment, overjet (OJ), overbite (OB), and cephalometric measurements, were recorded and analyzed. The results of this study indicate significant improvements in dental alignment and occlusion in the group of children who received interceptive orthodontic treatment. The average reduction in OJ was 3.5 mm, and the OB correction averaged 2.1 mm. Cephalometric analysis showed positive changes in skeletal relationships, with a mean reduction in the angle formed by point A, nasion (N) and point B. (ANB) angle of 2.8 degrees. These improvements were statistically significant compared to the control group (P < 0.05). Early orthodontic intervention, such as interceptive orthodontics, has a positive impact on dental and skeletal development in children with mixed dentition.

Prevalence and contributing factors of malocclusion in Zhuang children aged 7-8 years in southern China.

Malocclusion, a common oral health problem in children, is associated with several contributing factors. This study aimed to investigate the prevalence of mixed dentition stage malocclusion and its contributing factors in Chinese Zhuang children aged 7-8 years. Overall, 2,281 Zhuang children, about 7-8 years old, were randomly selected using a stratified whole-cluster sampling method from schools in counties in Northwestern Guangxi, China. The children were examined on-site for malocclusion and caries by trained dentists, and basic data on the children were collected using questionnaires, including age, sex, parental education, parental accompaniment, and children's knowledge of malocclusion and treatment needs. Data were analyzed using the chi-square test and logistic regression analysis. The total prevalence of malocclusion in Zhuang children aged 7-8 years was 58.5%, with the highest prevalence of anterior crossbite tendency, and the prevalence of anterior crossbite and anterior edge-to-edge occlusion was 15.1% and 7.7%, respectively. This was followed by an anterior increased overjet of 13.3% and an inter-incisor spacing of 10.3%. The lowest prevalence was 2.7% for anterior open bite. Sex, parental accompaniment, parental education, and decayed, missing, and filled teeth of the first primary molar were factors that contributed to malocclusion in Zhuang children. Malocclusion is a common oral problem among Zhuang children. Therefore, more attention must be paid to the intervention and prevention of malocclusion. The impact factors should be controlled as early as possible.

Influence of manufacturing surface topography on torque and load bearing capacity of hydro-viscous drive clutch under mixed lubrication stage

PurposeHydro-viscous drive (HVD) clutches are widely used in equipment requiring soft start, such as fans and pumps, to transmit torque and adjust speed by changing the gap distance between friction pairs. This paper aims to propose a novel two-parameter evaluation method for HVD during the mixed lubrication stage. The objective is to develop an effective model that establishes the relationship between these parameters and the actual surface topography.Design/methodology/approachIn the presented methods, the fractal features of the real manufacturing surface are calculated based on the power spectrum function by the ultra-depth three-dimensional microscope. After that, the hybrid friction model of the friction plate is established based on mixed elasto-hydrodynamic lubrication theory, boundary friction model and fractal theory. Then the torque and load bearing characteristics of the clutch are obtained, and the influences of the surface fractal features are investigated and discussed. Finally, the Weierstrass–Mandelbrot function is adopted for the surface topography characterization and evaluation.FindingsThe results indicate that the proposed method exhibits good accuracy, while the speed difference between the friction pair exceeds 2,500 rpm. It is concluded that this paper proposed a way to evaluate the torque and loading capacity of HVD considering the real manufacturing surface topography and is helpful for surface optimization.Originality/valueThe originality and value of this study lie in its development of a novel torque and load bearing capacity evaluation method for HVD in mixed lubrication stage, considering manufacturing surface topography and describing the real manufacturing surface.

Comparison between effects of mini-implant anchorage and face-bow anchorage in orthodontics for children.

To study the values of mini-implant anchorage in orthodontics for children in the mixed dentition stage, 78 children in the mixed dentition stage who had accepted orthodontic treatment in our hospital from January 2020 to January 2021 were enrolled into this study. All children were treated with straight-wire appliance. According to their anchorages, children were divided into observation group and control group based on the random number table. Children in the control group used face-bow to control the anchorages and children in the observation group used mini-implants to control the anchorages. After treatment, the upper central incisor convex distance difference, inclination angle of the upper central incisor, displacement of the molar, gingival health, masticatory function, treatment effect and adverse reaction rate of children in two groups were compared. One year after treatment, compared with children in the control group, children in the observation group had smaller the upper central incisor convex distance difference, inclination angle of the upper central incisor, displacement of the molar, small scores of plaque index (PLI), bleeding index (BI) and gingival index (GI), stronger biting force and higher masticatory efficiency, lower adverse reaction rate during treatment, better treatment effect, higher satisfaction of orthodontic treatment. And differences of all the above indexes were statistically significant (p < 0.05). Mini-implant anchorages have good stability and directive force, and have certain values in orthodontics for children in the mixed dentition stage.

Frequency and Pattern of Anterior Crossbite With Primary and Mixed Dentition in School Children

OBJECTIVES To determine the frequency and pattern of anterior crossbite with primary and mixed dentition in School Children. METHODOLOGY A descriptive cross-sectional study was conducted at Sharif Medical and Dental College, Lahore. This study included 296 participants having either deciduous or mixed dentition, no history of orthodontic treatment, aged between 3-11 years, both genders and Pakistani nationals. Participants with a history of trauma, cleft lip/palate, or any craniofacial syndrome and systemic disease were excluded. Participant’s age, gender, skeletal class, and anterior crossbite (ACB) were recorded. The Chi-square/Fisher exact test was run to compare ACB and their pattern among gender, age group, and skeletal class. RESULTSThere is a relatively high rate of anterior crossbite in this population, which is about 10%. The females were 169(57.09%) and males were 127(42.91%). The mean age was 6.92 ± 1.68 years. Overall, the ACB was present in 31(10.47%). The most common pattern of ACB was single incisor involvement (n=11, 35.48%) followed by two incisors (n=9, 29.03%), and the least was four incisors (n=5, 16.13%). The difference for ACB was statistically significant among skeletal classes (p&lt;0.001). The frequency of ACB was higher in skeletal class 1 (n=17, 54.84%) and in skeletal class 3 (n=13, 41.94%) than in class 2 (n=1, 3.23%). CONCLUSION The frequency of anterior crossbite is about 10%, which is relatively higher than in other populations. Most anterior cross bites are dental due to one or two incisor involvement, which can be corrected easily at the mixed dentition stage.

Mandibular Cortical Bone Evaluation in a Healthy Paediatric Population.

Changes in mandibular cortical bone have been documented in children with chronic diseases but not in healthy populations. We aimed to qualitatively and quantitatively evaluate the mandibular cortical bone of a healthy paediatric population using dental panoramic radiographs (DPTs). The secondary objective was to assess the effect of dental status on cortical bone. The DPTs of 660 individuals, aged 6-18 years, were evaluated by two blinded examiners. Bone was qualitatively categorized according to the Mandibular Cortical Index (MCI), and its width was calculated using the Mandibular Cortical Width Index (MCW). Differences between gender and age were tested using Fisher's exact and correlation with dental status with the chi-square test. A significant correlation was observed between bone morphology and gender, with girls having more frequent even and sharp endosteal margins than boys, who showed semilunar defects. The degree of erosion increased with age, as did bone thickness. A positive correlation between thickness and type of dentition was recorded, with normal bone predominating in children in the mixed dentition stage. Νο correlation was found between bone morphology or thickness and the factors associated with dental status. Bone quality and quantity vary significantly between different genders and age groups. Dental needs and treatment characteristics did not seem to affect the above parameters.

Bioglass 45S5, a relevant alternative to autogenous harvesting for secondary alveolar bone grafts in clefts? Retrospective study of one hundred surgeries

The secondary alveolar bone grafting (SABG) step restores the continuity of the alveolar bone necessary for dentition. Faced with the complications of autografts, synthetic biomaterials such as Bioglass (BG) 45S5 have been proposed. The objective was to evaluate the success rate of SABG with the addition of BG 45S5 and to highlight the prognostic factors.Patients who underwent operation between 2015 and 2021 and had follow-up cone-beam computed tomography (CBCT) were analyzed. Multivariate analysis was performed to determine factors influencing radiographic success. A total of 102 SABG were analyzed. They were unilateral total cleft lip and palate (49, 48.0%). The mean age at surgery was 9.32 ± 3.09 years. Surgeries were performed mainly outside a syndromic context and without a family history after orthodontic preparation.The radiographic success rate at 1 year was 80.4%. Mixed dentition stage (odds ratio [OR] = 7.3, p = 0.024), absence of syndromic context (OR = 20.7, p = 0.024) and female sex (OR = 4.88, p = 0.021) were factors predictive of surgical success.The use of BG 45S5 instead of autograft is relevant for SABG, with a 1-year success rate of over 80%. The stage of mixed dentition, the absence of syndromic context, and female sex were factors for good prognosis.

Progressive collapse behaviour of composite substructure with large rectangular beam-web openings

This study explores the progressive collapse resistance of composite substructures with the fully-welded connection (FC) and fully-welded connection with rectangular web openings (FCRO). Quasi-static loading tests were conducted to analyze failure modes, internal forces, and resistance mechanisms. The effect of substructure's boundary constraints on its anti-collapse behaviour was investigated through validated numerical models. The results show that the damage mode of the FC specimen involves tensile beam flange fracture at the beam root, while the FCRO specimen experiences fracture of the rectangular web openings. The resistance development of the FCRO specimen includes bending, bending-catenary mixed, and catenary stages, whereas the FC specimen undergoes bending and bending-catenary mixed stages. In the bending-catenary mixed stage, the FCRO specimen exhibits a 69.2% higher maximum resistance and a 15.3% larger displacement compared to the FC specimen. Despite the reduction in flexural capacity, incorporating large rectangular openings in the beam web enables plastic hinge to shift outward at the beam root, promoting the effective evolution of the composite beam’s axial force. The study derived expressions for the boundary axial constraint coefficient and attenuation coefficient to the FCRO specimen. Traditional strengthening methods were found to have limited effectiveness in enhancing the collapse resistance of unreinforced composite substructures. Consequently, a novel and effective construction measure was proposed, resulting in a significant enhancement of 78% in maximum resistance and 85% in corresponding deformation of the substructure.