Proportional Limit Research Articles

Ring Hoop Tension Test for yield strength estimation: Numerical analysis for a novel correlation method and applicability for mechanical testing of tubes and pipes

The tubes and pipes manufacturing industry characterizes the mechanical properties of their products with a wide selection of standards, but most of them are qualitative testing methodologies. To estimate the mechanical properties from a quantitative point of view there are limited options in standards. In that sense, the standard tensile test is the preferred alternative by the manufacturers, but this option limits the mechanical estimation for the longitudinal direction of the tube–pipe product. Particular efforts have been made to design an alternative mechanical testing procedure to characterize the mechanical properties in the hoop direction of pipes and tubes. The Ring Hoop Tension Test (RHTT) was designed to fill this gap, but it shows limitations related to the required tooling and the influence of the frictional contact between the tooling and the ring specimen. In the nuclear industry, the Small Ring Test (SRT), a miniature test derivated from the RHTT, has been investigated in recent years. In this investigation, a novel RHTT was designed to overcome the limitations of SRT and RHTT, and a new procedure was implemented to estimate the yield strength of tubes and pipes. Numerical FEM simulations were performed to reach an optimum estimation method for the yield strength with the specific geometry of the SRT and a wide selection of pipe geometries with the RHTT. A set of hypothetical materials were designed to perform these analyses, taking into account the influence of Young’s modulus, proportional limit, hardening coefficient (based on the Ramberg–Osgood law), and presence of Lüders bands straining. To verify the results obtained from this numerical FEM analysis, experimental tests (standard tensile tests and RHTTs) and metallographic analysis were performed on aluminum Al 6063 T6 and copper C12200 R360 tubes, showing the capability of this optimized RHTT to estimate the yield strength in the hoop direction for anisotropic tubes and pipes.

Concept of Placement of Fiber-Optic Sensor in Smart Energy Transport Cable under Tensile Loading.

Due to the exponential growth in offshore renewable energies and structures such as floating offshore wind turbines and wave power converters, the research and engineering in this field is experiencing exceptional development. This emergence of offshore renewable energy requires power cables which are usually made up of copper to transport this energy ashore. These power cables are critical structures that must withstand harsh environmental conditions, handling, and shipping, at high seas which can cause copper wires to deform well above the limit of proportionality and consequently break. Copper, being an excellent electric conductor, has, however, very weak mechanical properties. If plasticity propagates inside copper not only will the mechanical properties be affected, but the electrical properties are also disrupted. Constantly monitoring such large-scale structures can be carried out by providing continuous strain using fiber-optic sensors (FOSs). The embedding of optical fibers within the cables (not within the phase) is practiced. Nevertheless, these optical fibers are first introduced into a cylinder of larger diameter than the optical fiber before this same fiber is embedded within the insulator surrounding the phases. Therefore, this type of embedding can in no way give a precise idea of the true deformation of the copper wires inside the phase. In this article, a set of numerical simulations are carried-out on a single phase (we are not yet working on the whole cable) with the aim of conceptualizing the placement of FOSs that will monitor strain and temperature within the conductor. It is well known that copper wire must never exceed temperatures above 90 °C, as this will result in shutdown of the whole system and therefore result in heavy maintenance, which would be a real catastrophe, economically speaking. This research explores the option of embedding sensors in several areas of the phase and how this can enable obtaining strain values that are representative of what really is happening in the conductor. It is, therefore, the primary objective of the current preliminary model to try to prove that the principle of embedding sensors in between copper wires can be envisaged, in particular to obtain an accurate idea about strain tensor of helical ones (multi-parameter strain sensing). The challenge is to ensure that they are not plastically deformed and hence able to transport electricity without exceeding or even becoming closer to 90 °C (fear of shutdown). The research solely focuses on mechanical aspects of the sensors. There are certainly some others, pertaining to sensors physics, instrumentation, and engineering, that are of prime importance, too. The upstream strategy of this research is to come up with a general concept that can be refined later by including, step by step, all the aspects listed above.

ФУНКЦИОНАЛЬНО-СТРУКТУРНЫЕ СВЯЗИ В АРХИТЕКТУРЕ СОВРЕМЕННЫХ ПРОИЗВОДСТВЕННЫХ ЗДАНИЙ

today, up to 80% of buildings and structures are built on deep foundations, the main elements of which are concrete and reinforced concrete piles (hammered, bored and piles made according to CFA technology). Since the beginning of the mass use of drilling piles (the 60s of the last century), there is still a problem of ensuring the reliability of foundations, due to the fact that the process of installing piles is hidden from observation, and unacceptable defects may form in the pile trunks, which reduce the bearing capacity of piles and can lead the structure to an emergency condition. Pile construction technologies are constantly being improved, however, it is still not possible to avoid the appearance of defects in pile trunks because there are quite a lot of reasons for the formation of defects that it is not always possible to foresee and take into account. That is why, during the construction of deep foundations, output monitoring of the technical condition of drill pile shafts should be provided, which cannot be performed without the use of non-destructive diagnostic methods. The use of these methods and means, which implements them, should be mandatory to ensure the reliability and safety of the operation of buildings and structures and today is already provided for by numerous standards and regulatory documents. Currently, acoustic methods are mainly used for diagnostics, namely: single- and multi-channel acoustic logging; pulse Echo method with shock excitation of elastic waves (hereinafter referred to as the method of vibration-shock diagnostics). It should be noted that in the case of using high deformation to excite elastic waves, at which the impact energy on the end of the pile reaches the limit of proportionality, an assessment of the bearing capacity of experimental piles is given, and the low technique is used exclusively for diagnosing pile trunks. For a long time, these methods could not be widely implemented in the field. Their capabilities have increased significantly after the development of digital signal processing methods

Thermal stability of CVI and MI SiC/SiC composites with Hi-Nicalon™-S fibers

The influence of high-temperature argon heat-treatment on the microstructure and room- temperature in-plane tensile properties of 2D woven CVI and 2D unidirectional MI SiC/SiC composites with Hi-Nicalon™-S SiC fibers was investigated. The 2D woven CVI SiC/SiC composites were heat-treated between 1200 and 1600 °C for 1- and 100-hr, and the 2D unidirectional MI SiC/SiC composites between 1315 and 1400 °C for up to 2000 hr. In addition, the influence of temperature on fast fracture tensile strengths of these composites was also measured in air. Both composites exhibited different degradation behaviors. In 2D woven CVI SiC/SiC composites, the CVI BN interface coating reacted with Hi-Nicalon™-S SiC fibers causing a loss in fast fracture ultimate tensile strengths between 1200 and 1600 °C as well as after 100-hr isothermal heat treatment at temperatures > 1100 °C. In contrast, 2D unidirectional MI SiC/SiC composites showed no significant loss in in-plane tensile properties after the fast fracture tensile tests at 1315 °C. However, after isothermal exposure conditions from 1315° to 1400°C, the in-plane proportional limit stress decreased, and the ultimate tensile fracture strain increased with an increase in exposure time. The mechanisms of strength degradation in both composites are discussed.

Micromechanics Approach for the Overall Elastic Properties of Ceramic Matrix Composites Incorporating Defect Structures

Abstract The initial mechanical response of ceramic matrix composites (CMCs) is linear until the proportional limit. This initial response is characterized by linear elastic properties, which are anisotropic due to the orientation and arrangement of fibers in the matrix. The linear elastic properties are needed during various phases of analysis and design of CMC components. CMCs are typically made with ceramic unidirectional (UD) or woven fiber preforms embedded in a ceramic matrix formed via various processing routes. The matrix processing of interest in this work is the polymer impregnation and pyrolysis (PIP) process. As this process involves pyrolysis to convert a preceramic polymer into ceramic, considerable volume shrinkage occurs in the material. This volume shrinkage can lead to significant defects in the final material in the form of porosity of various size, shape, and volume fraction. These defect structures can have a significant impact on the elastic and damage response of the material. In this paper, a multiscale micromechanics modeling framework is developed to study the effects of processing-induced defects on the linear elastic response of a PIP-derived CMC. A combination of analytical and computational micromechanics approaches is used to derive the overall elastic tensor of the CMC as a function of the underlying constituents and/or defect structures. It is shown that the volume fraction and aspect ratio of porosity at various length scales play an important role in accurate prediction of the elastic tensor. Specifically, it is shown that the through-thickness elastic tensor components cannot be predicted accurately using the micromechanics models unless the effects of defects are considered.

Effects of applied stress and grain size on creep-rupture lifetime prediction for Haynes 282 alloy

A multiple-heat set of tensile and creep-rupture data generated from a single laboratory was used to establish and evaluate predictive equations for the average creep-limited lifetime of an aged wrought Haynes 282 alloy using two different time- and temperature-compensated parametric models (those of Larson and Miller and Wilshire et al.). The range of temperatures and stresses used to produce the creep-rupture data used in the analyses revealed that two distinct regimes, above and below the proportional limit, were necessary for more accurate predictions of creep lifetimes over the range of conditions studied. Furthermore, a 2x difference in grain size amongst the three heats revealed a breakdown in the relationship between ultimate tensile strength and creep-rupture time, thus impacting the predictive ability of the Wilshire model. Lifetime predictions based on the formulations from the respective models were compared to other available Haynes 282 datasets and found to reasonably replicate the experimental trends established in other studies.

Damage and failure analysis of a SiCf/SiC ceramic matrix composite using digital image correlation and acoustic emission

The analysis of failure behaviors of continuous fiber-reinforced ceramic matrix composites (CMCs) requires the characterization of the damage evolution process. In service environments, CMCs exhibit complex damage mechanisms and failure modes, which are affected by constituent materials, meso architecture, inherent defects, and loading conditions. In this paper, the in-plane tensile mechanical behavior of a plain woven SiC f /SiC CMC was investigated, and damage evolution and failure process were studied in detail by digital image correlation (DIC) and acoustic emission (AE) methods. The results show that: the initiation of macro-matrix cracks have obvious local characteristic, and the propagation paths are periodically distributed on the material surface; different damage modes (matrix cracking and fiber fracture) would affect the AE energy signal and can be observed in real-time; the significant increase of AE accumulated energy indicates that serious damage occurs inside the material, and the macroscopic mechanical behavior exhibits nonlinear characteristic, which corresponds to the proportional limit stress (PLS) of the material.

Structural Materials Durability Statistical Assessment Taking into Account Threshold Sensitivity

This work presents an experimental—analytical study of the possibility of applying the method of the greatest probability to evaluate the sensitive thresholds of the bottom (N0) and top (Nk) of the statistical distribution of the mechanical structural characteristics. For the structural materials alloyed steel 15Cr2MoVA, steel C45 and aluminium alloy D16T1, the statistical distribution of proportional limit, yield strength, ultimate tensile strength, reduction in area, cyclic stress was estimated, as well as the following statistical parameters: mathematical mean, average square deviation, dispersion, asymmetry, variation coefficient, and excess. Purpose: to determine whether the limits of the sensitivity of the statistical distribution of the mechanical characteristics have been computed using the maximum likelihood method. Value: there is a certain upward and downward flattening of the probability curves in the statistical distribution curves of the fatigue test results. This implies that the chosen law of the distribution of random variables has an effect on the appearance of errors. These errors are unacceptable given the importance of accurately determining the reliability and durability of transport means, shipbuilding, machinery, and other important structures. Our results could potentially explain why sensitive limits cannot be applied to the statistical distribution of the mechanical characteristics of structural materials.

Engineering of reference materials for providing traceability of measurements of mechanical stresses by acoustic type of nondestructive check

The article presents the investigation of a certified reference material (CRM) of the steels mechanical properties. At present traceability of measurement results of mechanical stresses is ensured to the standard of time, but not mechanical stresses, and a metrological approach to ensuring the uniformity of measurements of mechanical stresses requires the development of a basis for comparison.The aim of the work was the characterization and certification of standard samples of a special form, traceable to SI units-force and length, intended for transferring a unit of magnitude of mechanical stresses to measuring instruments that implement a temporary method of acoustic type of nondestructive check based on the phenomenon of acoustoelasticity. The article discusses the key stages of the development of reference materials: selection of the source material for reference materials; study of the homogeneity of the source material; carrying out experimental studies with the use of reference device (the state standard unit of strength of the 1st category) and establishing the metrological characteristics. As a result of type approval tests CRM was registered in the State Register of CRM’s as GSO 11544-2020/11545-2020. The certified characteristics of the CRM are proportional limit mechanical stress σpl; proof strength σ02 (plastic extension 0,2 %); tensile strength σв; modulus of elasticity E. Limits of the relative error of the certified values at a confidence level of 0,95 do not exceed 12 %. The authors believe that the CRM of the mechanical properties of steels GSO 11544-2020/11545-2020 will provide metrological traceability of the results of measurements of mechanical stresses by measuring instruments that implement the by acoustic type of nondestructive check, when using the GSO as a basis for comparison in the verification scheme.

Analysis of Measured Parameters in Relation to the Amount of Fibre in Lightweight Red Ceramic Waste Aggregate Concrete

The present study provides a correlation and regression analysis of lightweight waste aggregate concretes with varying degrees of fibre reinforcement. The concrete mix contains pre-soaked red ceramic waste aggregate, expanded clay coarse aggregate and Portland cement. Copper-coated crimped steel fibre was used as the reinforcement. The experimental results included properties measured by destructive test methods—compressive strength, splitting tensile strength, static modulus of elasticity, the limit of proportionality, shear strength; and by non-destructive test methods—dynamic modulus of elasticity and surface electrical resistivity. These properties were analysed to study the relevancy and significance between non-destructive and destructive methods of measurement in the case of different amounts of fibre. The results show differences in the degree of fit to the linear and quadratic regression curves for pairs of destructive and non-destructive test results. As expected, the linear relationship can be applied in a few cases, but the quadratic curve must be used for a few pairs. Another observation is that it is not possible to neglect the amount of fibre in the correlation analyses of the measured properties.

Mechanical Behavior of Reactive Powder Concrete Subjected to Biaxial Loading

To investigate the biaxial mechanical characteristics of reactive powder concrete (RPC), RPC plate specimens and bone‐shaped specimens were tested under compression‐compression and compression‐tension loadings, respectively. The strengths and strains of the specimens were recorded, and the crack patterns and failure modes in various stress states were examined. Based on the test data, the characteristics of biaxial strength were analyzed, and a biaxial failure criterion was established. The characteristics of major stress‐strain curves and failure modes in different biaxial stress states were determined. The results show that the ratio between the biaxial compression strength and the uniaxial compression strength was 1.44–1.58 for RPC. When the stress ratio under compression‐tension was −0.05, the tensile strength decreased by 48%. Under compression‐compression, the proportional limit of RPC was about 95%, and its peak strain was high. Under compression‐tension, as the compressive stress increased, the elastic modulus decreased, and the peak strain in the tensile direction increased. When the RPC specimens were under compression‐compression, the failure mode of RPC was splitting failure. Under compression‐tension, the failure mode changed from single‐crack tensile failure to multicrack compressive failure with increasing confining stress.

The flexural strength of glue laminated timber beams based on deflection and strain rate with four point bending loading system

The development of utilization of low quality wood as construction material is needed to reduce the exploitation of natural forests. However, low quality wood species have disadvantages in terms of mechanical properties. The mechanical properties of Sengon wood are relatively low, so it does not qualify as a structural element. Therefore, the system glulam can be applied to overcome this problem. The system glulam can produce relatively light structural elements with adequate performance. This system has been extensively developed, even at the stage of applying external reinforcement, to improve the performance of structural laminated beams. On that basis, this study aims to determine the flexural strength of laminated beams of Sengon wood as a low quality wood species. In order to achieve this goal, the laminated beam was tested using method four point bending test method. Tests were carried out on long span laminated beams (L = 2750 mm) to observe flexural strength. There are five (5) laminated blocks tested, namely (BLS-1, BLS-2, BLS-3, BLS-4 and BLS-5). Each group has dimensions of 55 mm in width and 155 mm in height. Each specimen consists of six layers of wood boards with a density Falcata 0.3 g / cm3. The thickness of each layer was 26 mm and bonded with resin urea formaldehyde cold setting. Double-sided adhesive laying of 350 gr / m2 at a compressive force of 2 MPa. The analysis result shows that the load-deflection relationship between BS-L consists of linear and nonlinear phases. The load performance characteristics of the two types of laminated beams are expressed as the ratio of the proportional limit load to the maximum load. The ratio value is expressed in the form P eBL-s = 0.7P max BL-S andM eBL-s = 0.7M max BL-S. This form is similar to previous studies with a Pe to Pmax ratio of 0.80.9. In this case, the average flexural strength of the laminated beam is 17 MPa with a maximum strain of 0.004.

Stress distribution at different deformation degrees in low carbon steel during cold deformation

The temperature change, i.e. stresses of low carbon steel during the cold deformation process was investigated in this study. During static tensile test, temperature changes were examined using thermography at different deformation degrees. It was found that there are temperature changes in the deformation zone during the cold deformation. The increase in temperature changes in the deformation zone during cold deformation occurs with an increase in the deformation degree. The largest localization of temperature change was measured at the moment of the test sample fracture when the maximum temperature change was 8.45 °C. A higher amount of temperature change of 5.39 °C was determined at tensile strength compared to the proportionality limit amount of -0.97 °C. It was found that there are differences between the amounts of temperature changes in the range from 0.87 °C to 1.91 °C with increasing of deformation degree of the tested steel. Calculated stress amounts proved and show the tendency that stress amounts increase as the temperature change increases in low carbon steel by increasing of deformation degree during cold deformation. It was determined deviations of the calculated stress amounts due to using the mathematical model for low carbon with niobium at the start of plastic flow.

Physical and Mechanical Properties of Selected Fruit-bearing and Underutilized Tree Species in the Philippines

To help augment the raw material supply of the wood-based industries, the study evaluated the physical and mechanical properties (PMP) of six selected timber species in the Philippines – four fruit-bearing and two underutilized tree species. The fruit-bearing species were “nangka” (Artocarpus heterophyllus Lamk.), “santol” [Sandoricum koetjape (Burm. F.)], “durian” (Durio zibethinus Murray), and “marang” [Litsea perrottetti (Blume) F. Vill.] collected from Bislig, Surigao del Sur (Caraga Region, Mindanao), while the underutilized tree species were “antipolo” [Artocarpus blancoi (Elmer) Merr] and “batino” (Alstonia macrophylla G. Donn) collected from Batangas City and Quezon Province (Region IV, Luzon), respectively. Physical properties included relative density (RD), moisture content (MC), and shrinkage. Mechanical properties covered modulus of rupture, stress at proportional limit, and modulus of elasticity in static bending; compression parallel-and perpendicular-to-grain; shear; hardness; and toughness. Standard testing procedures (ASTM-D143) were followed. Variations on the six species’ PMP were statistically analyzed, including the effect of individual trees and height levels. Among the six species, batino exhibited the highest RD (0.60), followed by nangka (0.49), antipolo (0.47), santol (0.46), marang (0.36), and durian (0.34). The MCs of nangka, santol, durian, antipolo, batino, and marang were 111.07, 121.21, 183.7, 152.68, 85.77, and 189.97% while the volumetric shrinkages (VSs) were 6.67, 6.86, 6.96, 9.07, 12.23, and 9.39%, respectively. The RD of batino was classified moderately high; those of nangka, santol, and antipolo were moderately low; and those of marang and durian were low. There was an inverse relationship between RD and MC in the six species. The VS values of nangka, durian, and santol were classified low; those of batino were medium; and those of antipolo and marang were moderately low. Overall, the mechanical properties of batino were moderately high; those of nangka, santol, and antipolo were moderately low; and those of durian and marang were low. The mechanical properties of the six species were compared with those of the “Philippine mahogany” species traditionally used for construction.

High-resolution in situ characterization of micromechanisms in CFRP laminates under mode II loading

Micromechanisms in carbon fiber reinforced plastics (CFRPs) were studied by in situ mode II fracture toughness tests using a high-resolution optical microscope. The fracture toughness tests on four-point bend end notched flexure specimens were interrupted between the proportional limit and the plateau region, followed by postmortem examination using a high-resolution X-ray computed tomography system to identify three-dimensional microdamage. The observations sequentially captured the formation of damage zone, which composed of plastic zone, fiber/matrix debonding, and microcracks. The microscopic failure process was correlated with the macroscopic behavior of CFRP laminates during mode II fracture toughness tests.

수중 폭발에 의한 함체의 비탄성 휘핑 응답에 관한 연구

The primary effect of the far-field underwater explosion (UNDEX) is the whipping of the ship hull girder. This paper aims to verify why inelastic effects should be considered in the whipping response estimations from the UNDEX simulations. A navy ship was modeled using Timoshenko beam elements over the ship length uniformly keeping the constant midship section modulus. The transient UNDEX pressure was produced using two types of the Geers-Hunter doubly-asymptotic models: compressible and incompressible fluids. Because the UNDEX model based on incompressible fluid assumption provided more increased fluid volume acceleration in the bubble phase, the incompressible fluid-based UNDEX model was adopted for the inelastic whipping response analyses. The non-linear hull girder bending moment-curvature curve was used to embed inelastic effects in the UNDEX analyses where the Smith method was applied to derive the non-linear stiffness. We assumed two stand-off distances to see more apparent inelastic effects: 40.5 m and 35.5 m. In the case of the 35.5 m stand-off distance, there was a statistically significant inelastic effect in terms of the average of peak moments and the average exceeding proportional limit moments. For the conservative design of a naval ship under UNDEX, it is recommended to use incompressible fluid. In the viewpoint of cost-effective naval ship design, the inelastic effects should be taken into account.

EXPERIMENTAL PRESSURES EXERTED BY MAIZE IN SLENDER CYLINDRICAL SILO: COMPARISON WITH ISO 11697

Pilot-scale test stations make it possible to obtain reliable and comparable results applicable to full–scale systems by conforming to specified proportional limits. Therefore, in this study, normal and frictional pressures were evaluated in a pilot-scale test station composed of a slender cylinder silo using maize, a free-flowing product, as the stored product. Temporal effects were analyzed and verified during filling, static, and discharge conditions. The maximum normal and frictional pressures were also evaluated. The results were compared with ISO 11697: 1995. During filling, accommodation peaks occurred only in the α: 30° hopper. In general, normal pressures were higher for the flat bottom whereas higher frictional pressures occurred for the 30° hopper. The maximum experimental pressures (normal and frictional) were lower than those provided by ISO 11697. Therefore, it is concluded that the coefficients used in the ISO standard are sufficient to promote safety in silo projects.

Structure of AlCoCrFeNi high-entropy alloy after uniaxial compression and heat treatment

In this study, we discuss the structure and properties of high-entropy AlCoCrFeNi alloy after casting, cold deformation, and heat treatment. Ingots of the investigated alloys were obtained by arc melting method in argon atmosphere. In order to ensure a homogeneous chemical composition, ingots were remelted several times. Cylindrical samples of 5 mm in diameter and 8 mm in height were cut from ingots by electrospark method for mechanical tests. Subsequently, samples were subjected to uniaxial compression by 5, 11, and 23 %. During the tests, compression curves were recorded, and limit of proportionality of the analyzed alloys was calculated. High-temperature annealing and thermal studies were performed using thermogravimetric analyzer. Thermal studies were carried out in a cyclic mode (3 cycles, including heating up to 1200 °C at a rate of 20 °C/min and cooling at a rate of 20 °C/min). High-temperature annealing was carried out at a temperature of 1200 °C for 5 hours. Such annealing of cast alloys promotes material homogenization and eliminates dendritic structure. The alloy presents limited plasticity. Grain boundaries are effective barriers preventing crack propagation. The studies indicate that plastic deformation has a significant effect on development of relaxation processes during subsequent heat treatment. An increase in strain during the compression leads to a higher rate of healing processes of defects in crystal structure.

Multiscale investigation on fatigue properties and damage of a 3D braided SiC/SiC + PyC/SiC composites in the full stress range at 1300 °C

Monotonic tensile and fatigue tests of a SiC/SiC composites were conducted at 1300 °C in the full stress range. The macroscopic behaviors were studied based on the strain data. The mesoscopic morphology was observed by X-ray computed tomography, and the microanalysis was conducted using SEM, EDS and XRD. Besides, the interfacial debonding strength (IDS) were measured by nano-indenter. The results reveal that the fatigue behaviors can be divided into three zones. The inelastic strains accumulation and stiffness reduction can be observed in all three zones due to matrix cracking, interface damage, and failure of fibers. The fatigue life is long in the run-out zone because the maximum stress is lower than the proportional limit stress (PLS). In the stress-insensitive zone, the fracture depends on high-temperature and oxidation effects. The failure in the stress-sensitive zone is dominated by the fiber strength. The interface behaviors greatly affect the fatigue life above the PLS.

Experimental investigation of longitudinal shear transfer in insulated concrete wall panels with notched insulation

Precast concrete sandwich panels are usually comprised of two concrete layers surrounding rigid insulation. The most commonly used insulation types are extruded (XPS) and expanded (EPS) polystyrene or polyisocyanurate (PIR). Studies have shown that walls with EPS insulation develop higher composite action than walls with XPS insulation because of EPS's surface roughness. In this study, notched insulation is investigated using double shear push-through tests on 24 specimens (18 notched and 6 un-notched). Specimens were constructed with X-shaped GFRP bar shear connectors . Test parameters include GFRP bar diameter (9.5 and 16.0 mm), insulation type (XPS, EPS, PIR), and notch type (trapezoidal, rectangular). Notches allow XPS to reach higher capacities since bond failure is mechanically prevented. On average, when the 9.5 mm connector was used with XPS, adding rectangular notches resulted in 37% and 50% increase in the connection proportional limit and peak load respectively, while trapezoidal notches gave lesser respective increases of 21% and 27%. These increases were not apparent in samples made with larger (16 mm) connectors since stiffer connectors attract more proportion of the load nor in samples with EPS or PIR insulation where the foam's surface roughness combined with stress concentrations at notches promoted diagonal shear failure. • Experimental push through investigation of insulated wall panels with rectangular and trapezoidal notches. • Using Digital Image Correlation (DIC) to measure wythe slip, notch effectiveness, and capturing failure modes. • Evaluating the stiffness degradation and residual deformation of panels under load-unload cycling.