Four-point Bending Tests Research Articles

Flexural Response of UHPC Wet Joints Subjected to Vibration Load: Experimental and Theoretical Investigation

This study aims to investigate the flexural performance of ultra-high-performance concrete (UHPC) wet joints subjected to vibration load during the early curing period. The parameters investigated included vibration amplitude (1 mm, 3 mm, and 5 mm) and vibration stage (pouring—final setting, pouring—initial setting, and initial setting—final setting). A novel simulated vibration test set-up was developed to reproduce the actual vibration conditions of the joints. The actuator’s reaction force time-history curves for the UHPC joint indicate that the reaction force is stable during the initial setting stage, and it increases linearly with time from the initial setting to the final setting, trending toward stability after 16 h of casting. Under the vibration of 3 Hz-5 mm, cracks measuring 14 cm × 0.2 mm emerge in the UHPC joint. It occurs during the stage from the initial setting to the final setting. The flexural performance of wet joint specimens after vibration was evaluated by the four-point flexural test, focusing on failure modes, load-deflection curves, and the interface opening. The results show that all specimens with joints exhibited bending failure, with cracks predominantly concentrated at the interfaces and the sides of the NC precast segment. The interfacial bond strength was reduced by vibrations of higher amplitude and frequency. Compared with the specimens without vibration, the flexural strength of specimens subjected to the vibration at 3 Hz-3 mm and 3 Hz-5 mm were decreased by 8% and 19%, respectively. However, as the amplitude and frequency decreased, the flexural strength of the specimens showed an increasing trend, as this type of vibration enhanced the compactness of the concrete. Additionally, the calculation model for the flexural strength of UHPC joints has been established, taking into account the impact of live-load vibration. The average ratio of theoretical calculation values to experimental values is 1.01, and the standard deviation is 0.04, the theoretical calculation value is relatively precise.

Experimental Study on the Flexural Performance of Geogrid-Reinforced Foamed Lightweight Soil

The flexural behavior of geogrid-reinforced foamed lightweight soil (GRFL soil) is investigated in this study using unconfined compressive and four-point bending tests. The effects of wet density and reinforcement layers on flexural performance are analyzed using load–displacement curves, damage patterns, load characteristics, unconfined compressive strength, and flexural strength. A variance study demonstrates that increasing the wet density significantly increases unconfined compressive strength. Bond stress mechanisms enable geogrid integration, efficiently reroute stresses internally, and greatly increase flexural strength. With a maximum unconfined compressive strength of 3.16 MPa and a peak flexural strength increase of 166%, this reinforcement increases both strength and ductility by changing the damage pattern from brittle to ductile. The principal load is initially supported by the foamed lightweight soil, and in later phases, geogrids take over load-bearing responsibilities. Additionally, the work correlates the ratio of unconfined compressive to flexural strength with wet density and informs the development of predictive models for unconfined compressive strength as a function of reinforcing layers and wet density.

Experimental study on flexural properties of superelastic SMA fiber reinforced ECC under monotonic load

Abstract To enhance the bending performance and crack control of ECC materials, a novel hybrid fiber-reinforced cement composite (SMAF-ECC) was developed by incorporating superelastic SMA fibers into PVA-ECC. Four-point bending tests under monotonic loading were performed to systematically examine the effects of SMA fiber content, diameter, and shape on the mechanical properties of thin plates, including cracking deflection, cracking strength, ultimate deflection, and flexural strength. Additionally, the bending toughness of the plates was assessed using the ASTM C108 toughness index. Moreover, a mesoscale numerical analysis model for SMAF-ECC thin plates was developed. The results indicate that SMA fibers notably enhance the flexural performance of the plates. As the SMA fiber content increases, both the initial cracking strength and ultimate deflection initially increase before decreasing, with optimal performance occurring at a fiber content of 0.5%, which improves these properties by 20.9% to 44.5% compared to specimens without SMA fibers. The flexural strength of the specimens continues to increase with fiber content, reaching a maximum improvement of 36.1%. Among the various fiber shapes, flat-headed SMA fibers exhibit the best performance in improving both flexural strength and ultimate deflection, with enhancements of 7.2% and 25.9%, respectively, compared to specimens without SMA fibers. Furthermore, the inclusion of SMA fibers markedly improves the bending toughness of the thin plates. The reliability of the numerical model was validated through comparisons between the simulation and experimental results.

Bone and Nerve Response to Sciatic Compression Neuropathy in a Rabbit Model.

Compression neuropathy is a prevalent medical condition, including common types such as carpal tunnel syndrome, cubital tunnel syndrome, sciatica, and many others. While the neurological consequences are well understood, the effects on bone properties and the potential downstream impact on fracture risk remain less clear. This study aimed to assess the influence of compressive neuropathy on bone properties using a rabbit model of sciatic nerve compression. We hypothesized that compressive neuropathy could adversely alter bone properties. Five New Zealand white rabbits underwent surgery to induce perineural scarring in the sciatic nerve, with the contralateral limb serving as a sham control. Bone mineral density (BMD), mechanical strength, and bone signaling proteins were evaluated through microcomputed tomography (μCT), four-point bending tests, and ELISA assays, respectively. Sciatic nerve histology was analyzed using VEGF and Nissl staining to assess axon and Schwann cell densities and quantified using image analysis software. The results showed no significant differences in BMD, biomechanical properties, or key bone signaling proteins (OPG and RANKL) between the affected and control tibias. These findings suggest that compression neuropathy does not significantly impact bone properties in the rabbit model.

Experimental and numerical analysis of self-compacting geopolymer concrete composite slab

Composite slab systems have earned high regard in the building industry as a fast-track construction and an economical approach. Geopolymer concrete has been recognised as an environmentally friendly material that produces lower CO2 emissions than conventional cement-based concrete. This paper compares the structural and shear bond performance of a composite slab incorporating self-compacting geopolymer concrete (SCGC) to that of a normal concrete (NC) composite slab. This research also focuses on the structural performance of SCGC composite slab reinforced with a 2% basalt fibres (BFs) dosage. BFs have been acknowledged for their sustainable feature and outstanding mechanical properties, making them a feasible choice compared to their counterparts. This study examined full-scale composite slabs made of NC, SCGC and self-compacted geopolymer concrete reinforced with BFs (SCGCB), with a targeted compressive strength of 32MPa, subjected to a four-point flexural test. Composite slabs were tested with two different shear spans of 600mm (long) and 300mm (short). The performance of composite slabs was assessed in terms of failure modes, load-deflection response, a flexural strain developed at concrete and profiled sheet surfaces, load-slip response, moment capacity, energy-based ductility of a composite slab, and shear bond resistance. SCGC showed an average 7.96% lower shear bond capacity than the NC composite slab. SCGCB composite slabs exhibited an overall noticeable improvement in load-carrying capacity, strain capacity, ductility and shear bond resistance compared to SCGC composite slabs. A nonlinear finite element model was developed to predict the shear bond capacity of SCGC and SCGCB composite slabs. The developed model was validated against the experimental results, showing good agreement with a variance of less than 10%

Reforço à flexão de vigas em concreto armado com concreto têxtil de fibra de vidro álcali-resistente com diferentes tratamentos superficiais

Abstract Textile reinforced concrete emerges as an alternative for the strengthening of reinforced concrete structures. However, as a relatively new material, there is still no regulatory body or standardization that standardizes the manufacturing and application processes of the material, which generates significant differences regarding its characteristics and properties. From this perspective, this study seeks to experimentally evaluate the mechanical performance of textile reinforced concrete when applied as reinforcement of reinforced concrete beams subjected to four-point bending tests, using the alkali-resistant fiberglass textile produced in Brazil, TEXIGLASS AR-360-RA-04. As an exploratory study, the experimental program consists of fourteen reinforced beams and one rectangular cross-section reference beam (120 mm wide, 200 mm high, and 1500 mm long), totaling fifteen beams. As variables, the bond strength at the textile-matrix interface is investigated based on (a) the type of matrix (industrialized polymer mortar or self-compacting mortar) and (b) the surface treatment of the textile in four configurations: uncoated textile (UT), coated with epoxy (E), fully coated with epoxy and sand (ES) or fully coated with epoxy and partial sand (EPS). From the results, it was mainly found that: all reinforced beams showed increases in (a) load-carrying capacity, (b) ductility and (c) toughness. Despite the great variability of results, the coating technique in the EPS textile specimens proved promising.

Optimization and mechanical response of modular infusion compaction and normalization

Modular infusion (MI) is utilized to eliminate dry spot defects within complex multi-architecture composites by segregating and controlling flow fronts in-process. Compaction, employed to arrest in-plane flow, results in a crimp witness, which can be eliminated through MI fiber bed normalization. However, the MI normalization techniques generate voids within the cured components. To study the mechanisms that control the MI fiber bed normalization process, an in-process X-ray computed tomography (XCT) approach is developed to provide a visualization of fiber bed thickness and void distribution. Inner bag regulation during normalization is identified as the primary cause of the void generation. C-scans on a cured panel corroborate XCT findings, as well as validating the quality of the panel produced for subsequent mechanical test samples. Hence, it is demonstrated that the approach enables the optimization of a MI manufacturing process, which is supported by the findings of the mechanical characterization campaign. Flexural tests were carried out in three and four-point bend testing using samples cut from the panel, with Digital Image Correlation (DIC) providing comparative measurements for a baseline and MI case. Flexural testing of MI samples showed that a comparable mean strength and stiffness to that of the baseline material was achieved, demonstrating complete restoration of material thickness and mechanical properties during the optimised MI process.

Structural Performance of Reinforced Concrete Beams with Steel Fibres as Secondary Reinforcement: Experimental and Pre-peak Numerical Modelling

This research consists of an experimental and a numerical investigation into improving the structural performance of reinforced concrete (RC) beams by incorporating hooked-end steel fibres. Experimentally, steel fibres were added to the concrete matrix of 80 mm × 180 mm × 1500 mm RC beams with fibre contents of 0%, 0.5%, and 1%, without replacing traditional reinforcement bars. Each beam underwent a four-point flexural test using a hydraulic press under static loading to evaluate the influence of fibres on flexural behaviour. The numerical analysis aimed to model the macro-scale flexural behaviour of RC beams using a 3D finite element approach in ABAQUS. Challenges in modelling steel fibres include their discrete nature and computational demands due to intricate meshing and convergence issues. The Simplified Concrete Damaged Plasticity Model was used to characterize the compressive and tensile behaviours of plain and steel fibre reinforced concretes. Nonlinear finite element analysis was performed to predict pre-peak load versus mid-span deflection and crack propagation. The model, which does not explicitly simulate steel fibres, was validated against experimental data, showing strong agreement and confirming its effectiveness in capturing the flexural behaviour of steel fibre reinforced concrete beams. Experiments Results showed that steel fibres enhance the flexural performance. Beams with steel fibres exhibited higher first crack loads, ultimate loads, flexural strengths, and toughness. Additionally, the fibres increased crack numbers, reduced crack spacing and length, and improved post-cracking behaviour. The simulation results were subsequently validated against experimental data. The results of the numerical finite element analysis were in good agreement with those of the experiments.

Development of an Equivalent Analysis Model of PVB Laminated Glass for TRAM Crash Safety Analysis.

This study focuses on an equivalent model of Polyvinyl Butyral (PVB) laminated glass to simulate the Head Injury Criterion (HIC) when a pedestrian collides with a TRAM. To simulate the collision behavior that occurs when a pedestrian's head collides with PVB laminated glass, a comparison was made between the results of the widely used PLC model for PVB laminated glass modeling and an actual dynamic head impact test. The material properties of the tempered glass and PVB film used in the PLC and equivalent models were obtained via four-point bending tests and tensile tests, respectively. The proposed equivalent model is developed by assigning the thickness, material properties, and positional information of each layer in the multilayer PLC model to the integration points of the shell element. The results of the equivalent analysis model were found to accurately simulate the collision behavior when compared with the results of both the dynamic head impact test and the PLC model. Moreover, the analysis cost improved to approximately 15% of that of the traditional PLC model.

Fatigue Life of Pre-Cut Seam Asphalt Mixture Composite Beams: A Combined Study of Fatigue Damage Evolution and Reflective Cracking Extension

This study investigated the impact of reflective cracking on the fatigue performance of asphalt pavements after milling and resurfacing under various conditions. Fatigue life was assessed through four-point flexural fatigue tests, while the crack extension pattern of composite beams was analyzed by digital image correlation (DIC) at both macroscopic and microscopic scales. Evaluation parameters such as stress ratios, immersion time, porosity, and types of viscous oils were assessed. A fatigue life prediction model of composite beams was established, accounting for the combined influence of these factors. To enhance the accuracy of determining composite beam failure, the critical fatigue damage was calculated by defining the damage variable in terms of the dynamic modulus. A nonlinear fatigue damage model was proposed, incorporating this critical damage under the combined influence of various factors. Additionally, a modified logistic function model was developed to describe the relationship between crack extension and failure life under different stress ratios, porosities, and viscous layer oil conditions. It was found that the modulus decay curves and the crack extension curves intersected at different stress levels as the life ratio increased. At the intersection, the modulus ratios were consistently around 0.55, marking the transition of the specimen from a stable to an unstable state. Beyond this point, the crack rapidly propagated, leading to a sharp reduction in the modulus until the specimen ultimately failed. Our results provide a basis for timing and conservation decisions.

From Crop Residue to Corrugated Core Sandwich Panels as a Building Material.

This study explores the potential of using underutilized materials from agricultural and forestry systems, such as rice husk, wheat straw, and wood strands, in developing corrugated core sandwich panels as a structural building material. By leveraging the unique properties of these biobased materials within a corrugated geometry, the research presents a novel approach to enhancing the structural performance of such underutilized biobased materials. These biobased materials were used in different lengths to consider the manufacturing feasibility of corrugated panels and the effect of fiber length on their structural performance. The average lengths for wood strands and wheat straws were 12-15 cm and 3-7.5 cm, respectively, while rice husks were like particles, about 7 mm long. Due to the high silica content in rice husk and wheat straw, which negatively impacts the bonding performance, polymeric diphenylmethane diisocyanate (pMDI), an effective adhesive for such materials, was used for the fabrication of corrugated panels. Wood strands and phenol formaldehyde (PF) adhesive were used to fabricate flat outer layers. Flat panels were bonded to both sides of the corrugated panels using a polyurethane adhesive to develop corrugated core sandwich panels. Four-point bending tests were conducted to evaluate the panel's bending stiffness, load-carrying capacity, and failure modes. Results demonstrated that sandwich panels with wood strand corrugated cores exhibited the highest bending stiffness and load-bearing capacity, while those with wheat straw corrugated cores performed similarly. Rice husk corrugated core sandwich panels showed the lowest mechanical performance compared to other sandwich panels. Considering the applications of these sandwich panels as floor, wall, and roof sheathing, all these panels exhibited superior bending performance compared to 11.2 mm- and 17.42 mm-thick commercial OSB (oriented strand board) panels, which are commonly used as building materials. These sandwich structures supported a longer span than commercial OSB panels while satisfying the deflection limit of L/360. The findings suggest the transformative potential of converting renewable yet underutilized materials into an engineered concept, corrugated geometry, leading to the development of high-performance, carbon-negative building materials suitable for flooring and roof applications.

Effect of Concrete Compressive Strength on the Bond Performance of Flexural Prisms Externally Strengthened with CFRP Laminates

This paper presents a study from an ongoing research project on the bond performance of flexural prisms strengthened using carbon-fiber-reinforced polymer (CFRP) laminates. The primary objective is to evaluate the effect of normal-strength concrete (NSC – 30MPa) and high-strength concrete (HSC - 50MPa) on the bond performance of plain concrete prisms notched at the mid-span and strengthened using CFRP laminates. Six of the twelve plain concrete prisms were strengthened using CFRP laminates, while the remaining prisms were unstrengthened to serve as control specimens. After achieving 28 days of curing in standard lab conditions, all prisms were tested under a four-point bending test. The ultimate mid-span deflection, maximum and ultimate strains at the mid-span, strain distribution at different positions along the length of the laminate, and bond/shear stress versus slip were analyzed to evaluate the bond performance of flexural prisms. The average ultimate load-carrying capacities and mid-span deflection of the NSC and HSC groups were 31.33 and 35.02 kN and 0.55 and 1.54 mm, respectively. The average CFRP strain values at the mid-span corresponding to the ultimate load were 5005 and 3544 με for the NSC and HSC groups, respectively. The maximum attained bond-stress values for NSC and HSC groups were 1.71 and 1.42 MPa, respectively. The corresponding values for slip at maximum bond stress are 0.27 and 0.24 mm for the two groups, respectively. It was concluded from the study that the concrete compressive strength has minimal effect on the flexural bond performance of concrete prisms externally bonded with CFRP laminates.

Impact of Temperature and Humidity on Key Mechanical Properties of Corrugated Board

This research explores how temperature and relative humidity impact the mechanical properties of corrugated cardboard. Samples were treated under a range of controlled climate conditions in a climate chamber to simulate varying environmental exposures. Following this conditioning, we performed a series of mechanical tests: the Edge Crush Test (ECT) to assess compressive strength, four-point Bending Tests (BNTs) in both the Machine (MD) and Cross Directions (CD) to evaluate bending stiffness, Sample Torsion Tests (SSTs) for shear stiffness, and Transverse Shear Tests (TSTs) to measure torsional rigidity. By comparing results across these tests, we aim to determine which mechanical property shows the highest sensitivity to changes in humidity levels. Findings from this study are expected to offer valuable insights into the environmental adaptability of corrugated board, particularly for applications in packaging and storage, where climate variability can affect material performance and durability. Such insights will support the development of more robust and adaptable packaging solutions optimised for specific climate conditions.

Shape Optimization and Experimental Investigation of Glue-Laminated Timber Beams.

This study investigated the optimal shape of glue-laminated timber beams using an analytical model of a slender beam, taking into account the anisotropy of its strength properties as well as boundary conditions at the oblique bottom face of the beam. A control theory problem was formulated in order to optimize the shape of the modeled beam. Two optimization tasks were considered: minimizing material usage (Vmin) for a fixed load-carrying capacity (LCC) of the beam and maximizing load-bearing capacity (Qmax) for a given volume of the beam. The optimal solution was found using Pontryagin's maximum principle (PMP). Optimal shapes were determined using Dircol v. 2.1 software and then adjusted according to a 3D finite element analysis (FEA) performed in Abaqus. The final shapes obtained through this procedure were used in the CNC-based production of three types of nine beams: three reference rectangular beams, three Vmin beams, and three Qmax beams. All specimens were subjected to a four-point bending test. The experimental results were contrasted with theoretical assumptions. Optimization reduced material usage by ca. 12.9% while preserving approximately the same LCC. The maximization of LCC was found to be rather unsuccessful due to the significant dependence of the beams' response on the highly variable mechanical properties of GLT.

Study on Mechanical Properties and Carbon Emission Analysis of Polypropylene Fiber-Reinforced Brick Aggregate Concrete.

Given the current construction waste accumulation problem, to utilize the resource of red brick solid waste, construction waste red brick was used as a concrete coarse aggregate combined with polypropylene fiber to prepare PPF (polypropylene fiber)-reinforced recycled brick aggregate concrete. Through a cube compression test, axial compression test, and four-point bending test of 15 groups of specimens, the influences of the aggregate replacement rate of recycled brick and the PPF volume on the mechanical properties of recycled brick aggregate concrete reinforced by PPF were studied, and a strength parameter calculation formula was constructed and modified based on the above. Finally, combined with a life cycle assessment (LCA), the carbon emissions of raw materials were analyzed and evaluated. It was found that the mechanical properties of recycled concrete enhanced by PPF are critical at an addition rate of 50% and then decrease slowly with an increase in the aggregate content. PPF effectively alleviates the problem of strength reductions caused by regenerated aggregate substitution through the fiber-bridging effect. Based on the experimental data, a mechanical transformation model considering fiber reinforcement and BA weakening was constructed, and the regression accuracy R2 was around 0.90. The environmental benefit obtained when only replacing the natural aggregate is low. Although the incorporation of fiber improves the carbon emissions of the material to a certain extent, the benefits are more noticeable compared with the increase in strength. The results show that garbage recovery and strength demand benefits are achieved when the amount of recycled brick aggregate is 50% of the total. The strength conversion model established in this paper has of high accuracy and was created with careful consideration of fiber reinforcement and the regenerated aggregate weakening correction, providing it with more robust adaptability and extensibility. The mechanical properties of the recycled brick aggregate concrete enhanced by PPF are excellent and sustainable when the replacement rate of BA is 50% and the PPF volume is 0.1%.

Thermal and Mechanical Performances Optimization of Plaster–Polystyrene Bio-Composites for Building Applications

Polystyrene is renowned for its excellent thermal insulation due to its closed-cell structure that traps air and reduces heat conduction. This study aims to develop sustainable, energy-efficient building materials by enhancing the thermal and mechanical properties of plaster–polystyrene bio-composites. By incorporating varying amounts of polystyrene (5% to 25%) into plaster, our research investigates changes in thermal conductivity, thermal resistance, and mechanical properties such as Young’s modulus and maximum stress. Meticulous preparation of composite samples ensures consistency, with thermal and mechanical properties assessed using a thermal chamber and four-point bending and tensile tests. The results show that increasing the polystyrene content significantly improved thermal insulation and stiffness, though maximum stress decreased, indicating a trade-off between insulation and mechanical strength.

Experimental Study on the Flexural Performance of Composite Beams with Lipped Channels.

This study conducted experiments to investigate the flexural behavior of steel-concrete composite beams with U-shaped sections, utilizing cold-formed lipped channels as web components. To enhance both flexural and shear performance, trapezoidal plates were added to the lower sides of the composite beams. A total of ten specimens were fabricated, with variables defined according to the following criteria: presence of bottom tension reinforcement and bottom studs, thickness of the trapezoidal side plates (6 mm and 8 mm), and the welding method. Four-point bending tests were conducted, and all specimens exhibited typical flexural failure at the ultimate state. Specimens with bottom tension reinforcement, specifically those in the H5-T6 and H5-T8 series, demonstrated increases in ultimate load of 28.8% and 33.5%, respectively, compared to specimens without tension reinforcement. The use of lipped channels enabled full composite action between the concrete and the steel web components, eliminating the need for stud anchors. Additionally, it was confirmed that the plastic neutral axis, reflecting the material test strengths, was located within the concrete slab as intended. This study also compared the design flexural strengths, calculated using the yield stress distribution method from structural steel design standards such as AISC 360 and KDS 14, with the experimental flexural strengths. The comparison was used to evaluate the applicability of current design standards.

Exploring physical and thermo-elastic properties of two tropical wood species: insights from probabilistic analysis

ABSTRACT This study aimed to investigate the influence of temperature on the bending strength and modulus of elasticity of the tropical wood species: Pterocarpus soyauxii and Triplochiton scleroxylon. A probabilistic analysis of the fracture behavior of these two species is also conducted, utilizing a two-parameter Weibull distribution to assess the effect of temperature. Bending properties were measured for temperature ranges from 25°C to 100°C using four-point static bending tests. The findings reveal that temperature significantly impacts moisture content, bending strength, and longitudinal modulus of elasticity. Bending strength decreases linearly from 44 MPa to 32 MPa for Triplochiton scleroxylon and from 91 MPa to 65 MPa for Pterocarpus soyauxii. The modulus of elasticity shows random variation with temperature; it increases between 25°C and 45°C then decreases between 45°C and 100°C. The Weibull modulus varies between 9.2 and 15.6 for Triplochiton scleroxylon, and Pterocarpus soyauxii presents lower values which are between 3.4 and 6.1. In general, for both species, the Weibull modulus evolves very randomly with temperature. These results give engineers an overall understanding of the thermomechanical behavior of these tropical wood species.

An Experimental Study on Repairing of Reinforced Concrete Beams Having Damaged Longitudinal Bars

The objective of this study was to systematically evaluate the effects of different repair methods to determine optimal strategies for enhancing the load-carrying capacity of damaged reinforced concrete beams. During construction or rehabilitation, some openings may be created in structural members for various reasons, either intentionally or accidentally. While creating these gaps, damage may occur to the lower reinforcement of the beam. Within the scope of this paper, the effects of these openings were studied, and the different techniques to be used in the repair of damaged reinforced concrete beams were investigated. This study discusses an experimental analysis of ten beams under bending loads. An opening gap was formed at the lower mid-span of all beams except the reference beam, with the main reinforcement in these openings being cut. The damaged beams were then repaired with various techniques, including fiber-reinforced polymer (FRP) sheets and different reinforcement bars. The experiments of all beams were carried out by applying the four-point bending test model. The results showed that all repaired beams had significant enhancements in behavior and load, stiffness, ductility, and energy consumption capacities compared to the damaged beam.

Bending properties of human cartilaginous ribs and costal cartilage material vary with age, sex, and calcification.

Costal cartilage plays an important functional role in the rib cage, but its mechanical properties have not been well characterized. The objective of this study is to characterize the properties of human costal cartilage and examine the effects of age, sex, rib level, and degree of calcification. We obtained cadaveric costal cartilage samples of ribs 3-6 with intact perichondrium from 24 donors (12 females and 12 males) evenly distributed by age (range 47-94yr). Peripheral QCT scans were used to quantify geometric properties (area moments) and tissue calcification (as volume, length, and classified as central, peripheral, and mixed). Four-point bending tests were performed on each sample, and bending stiffness and modulus outcomes were evaluated by fitting data from mechanical testing with non-linear pseudo-elastic models (composed of linear and cubic components, separated into loading and unloading regimes). Effects of sex, age, rib level, and cartilage calcification on bending stiffness and modulus outcomes were assessed with mixed-effects regression models. Cartilage size (area moment) was larger in males than females and positively associated with age, while there was more calcification volume in cartilage of females than males. During loading, stiffness (linear and cubic) was larger in males, while modulus (linear and cubic) was larger in females. Linear stiffness and modulus were both negatively associated with age, positively associated with calcification, and varied between rib levels. Cubic (nonlinear) components of stiffness and modulus were positively associated with calcification and varied by rib, while modulus (but not stiffness) was negatively associated with age. During unloading, the linear stiffness and modulus values were much lower, though some similar associations were found. Overall, this study adds to our understanding of the behavior of costal cartilage as a nonlinear visco-elastic material, and the effects of sex, aging, and calcification on mechanical behavior.