Joint Geometry Research Articles

Alterations of generic musculoskeletal models to incorporate realistic knee joint and muscle geometry for biomechanical analyses during healthy gait: a narrative literature review

Alterations of generic musculoskeletal models to incorporate realistic knee joint and muscle geometry for biomechanical analyses during healthy gait: a narrative literature review

Alterations of generic musculoskeletal models to incorporate realistic knee joint and muscle geometry for biomechanical analyses during healthy gait: A Narrative Literature Review

Alterations of generic musculoskeletal models to incorporate realistic knee joint and muscle geometry for biomechanical analyses during healthy gait: A Narrative Literature Review

Disassembly analysis of hot-melt adhesive in mechanical joints

The mechanical properties of a commercially available hot-melt adhesive (HMA) have been studied under different environmental and loading conditions. To date, disassembly analyses including triggering features, design parameters, and time have not been fully investigated in the literature. In this study, experimental parametric studies have been performed on single lap joints considering the geometric features of the joint and a combination of thermo-mechanical effects. Disassembly time has been assessed through experimental analysis, considering variations in geometry, the use of alternative heat sources and different load conditions. Use of a heat gun as the heat source was found to lead to the highest variation in disassembly time compared to a static climatic chamber (i.e., industrial oven). In relation to the joint geometry, the disassembly time was mostly affected by the overlap length rather than the type or thickness of the base material. The outcomes of this study will drive the design of adhesive joints in mechanical applications, providing design-for-disassembly guidelines for the development of reversible joints employing hot-melt adhesives.

Solder Joint Geometry Effects on Thermomechanical Fatigue Lifetime of End-Capped Chip Component Assemblies

Solder Joint Geometry Effects on Thermomechanical Fatigue Lifetime of End-Capped Chip Component Assemblies

Sustainable Furniture Joints: Leveraging Fused Deposition Modeling (FDM) for Eco-Friendly Design

Integrating form, function, and material selection has been fundamental in furniture design and production. Traditional methods, particularly in joint creation, demand skilled craftsmanship and time-intensive processes. However, the emergence of 3D printing technology, specifically fused deposition modeling (FDM), has revolutionized furniture joint production. This study investigates the sustainable application of FDM for creating furniture joints, emphasizing eco- friendly design and efficient material utilization. To optimize the joinery system using 3D printing, researchers have conducted structured interviews with experts in the Malaysian 3D printing field. Their insights guided the development of guidelines for selecting appropriate materials and optimizing joint geometries. In furniture manufacturing, FDM enables precise joint components through layer-by- layer construction using thermoplastic materials. Unlike traditional methods that often result in wood waste, FDM minimizes material consumption. Designer- generated joint designs produced seamlessly via 3D printing reduce production time and enhance precision. Cost-effectiveness further positions FDM as a sustainable alternative for furniture production. This research focuses on two commonly used FDM materials: Acrylonitrile Butadiene Styrene (ABS) and Polylactic Acid (PLA). By providing guidelines for selecting appropriate materials, it will eventually empower designers and manufacturers to create furniture joints that align with sustainability goals. The resulting joints exhibit superior accuracy compared to manual craftsmanship, contributing to both environmental conservation and innovation within the Malaysian furniture industry

Recent Advances in Adhesive Bonding of 3D-Printed Parts and Methods to Increase their Mechanical Performance

The use of additive manufacturing (AM) has revolutionized the production of polymer-based materials, offering a wide range of design possibilities and geometric complexity. However, due to the limitations of 3D printers to produce large parts, the parts often must be printed in several separate components and further joined together to obtain the final 3D-printed part. 3D printing can be used to produce only the most complex parts, which can be further combined with simple, non-printed parts from other materials to make the final product. One way to join 3D-printed part is an adhesive-bonded method. This paper focuses on the recent advances in adhesive bonding techniques for 3D-printed parts and explores various methods to enhance their mechanical performance. The benefits and limitations of each technique were discussed, and highlighted promising paths for future research. Finally, this paper provides a comprehensive overview of the current strategies to improve the mechanical performance of adhesive joints with AM-based adherents, offering guidance for the design and fabrication of high-performance structures in a range of applications. It was concluded that the configuration of the bonding area represents an essential parameter that directly influences the bonding strength and overall structural integrity of AM adhesive joints, and that the implementation of customized joint geometries can lead to a substantial enhancement in the joint strength of 3D-printed parts. The incorporation of reinforcing materials, optimization of the printing parameters of adherents, pre and post-treatment methods show potential in enhancing the bonding strength of the 3D-printed joints. The synergistic integration of these cutting-edge technologies can yield mutual advantages that complement each other, ultimately resulting in an enhanced overall performance for AM parts.

Finite Element Analysis of Corrosion Tubular T-Joint Repaired with Grouted Clamp

A finite element (FE) analysis of corroded circular hollow section T-joints repaired using grouted clamps is presented in this study. To ensure an accurate simulation, experiments on a T-joint with uniform corrosion and an intact T-joint with grouted clamp are reproduced separately using an FE model. The experimental and FE modeling results correlate closely, displaying similar failure behaviors and load–displacement responses. Subsequently, a total of 56 FE T-joint models with varying degrees of corrosion on the chord, repaired by grouted clamp, were then analyzed numerically. The corrosion was artificially applied to the chord’s outer surface at depths of 10%, 20%, and 30% of the chord’s thickness. The models also account for variations in joint geometry, dictated by parameters β and γ, which range from 0.565 to 0.678 and from 21 to 28, respectively. Furthermore, grouted clamp’s properties were examined, including sleeve length, thickness, strength, as well as the thickness and strength of the grout, in relation to the complexity of the repair. The grouted clamp demonstrated significant repair capability, increasing the ultimate strength of the corroded joint by up to 2.23 times. Reinforcements that are both thicker and longer substantially enhance the joint’s ultimate strength. However, inappropriate repair construction results in an abrupt termination of the load–displacement curve and a brittle failure phenomenon outside reinforced chord region. Additional weight from the grouted clamp requires reasonable control, and sleeve overlapping ratio should be guaranteed to be greater than 0.7. The joint bearing capacity can be efficiently increased by thicker grouts and sleeves only in ductile failure cases. The confinement effect and mechanism of the grouted clamp in joint deformation were visually analyzed as stress distribution from FE analysis results. Finally, a prediction equation is proposed to estimate the static strength of the repaired joint through regression analysis.

Back-analysis of the paraglacial slope failure at Grewingk Glacier and Lake, Alaska

The relationship between rock-slope failure and glacier retreat is complex, and paraglacial failures often lack clearly identified triggers. To better understand the role of glacier retreat in rock-slope failures, we analysed the processes that led to the October 1967 Grewingk landslide in Kachemak Bay State Park on the Kenai Peninsula, Southcentral Alaska. The rock material collapsed onto the glacier toe and into its pro-glacial lake and produced a tsunami wave that swept the outwash plain. On the day of the failure, rainfall and snowmelt were well within normal ranges, and seismic records show no significant shaking. Three years prior to the 1967 failure, the slope withstood the second largest earthquake ever recorded (Great Alaskan earthquake, MW 9.2). We reassessed the volume of the failure by differencing pre- and post-digital terrain models and found a value of 20–24 × 106 m3, which is four times smaller than a previous estimate. The back analysis of the Grewingk landslide is based on remote sensing data and field measurements including aerial satellite image analysis, detailed surveying and understanding of the structural geology, a kinematic analysis, and runout modelling. Our research provides an example of a major paraglacial failure that lacks an obvious trigger and points to several geological factors and changing environmental conditions that likely promote such failures. This study further indicates that the Grewingk landslide, pre-conditioned by the geometry of faults and joints, may have reached a critical stability state due to internal processes and the potential combined effects of seismic activity and glacier retreat prior to the collapse.

Laser beam oscillation welding for fatigue properties enhancement of tailor-welded blanks

Dissimilar thickness laser welded tailored blanks of two low-alloyed carbon steel grades were fabricated. Laser welds made without beam oscillation exhibited serious root undercuts. Although these notches did not degrade the tensile strength, they were detrimental to the fatigue lifetime of a weld joint. Therefore, laser welds with three different beam oscillation modes to modify the root were examined. Application of beam oscillation improved fatigue properties in all tested cases. The best results were achieved with line oscillation, even though this mode did not suppress weld root notches, suggesting other factors, besides joint geometry, contributing to the resulting fatigue properties.

Revealing evolutions of intermetallics in a solder joint under electromigration: A quasi-in situ study combining 3D microstructural characterization and numerical simulation

The evolution of primary and interfacial intermetallic compounds in solder joints during electromigration (EM) significantly influences the mechanical properties and reliability of solder joints. In this work, by combining high-resolution x-ray computed tomography and finite element modeling, the 3D evolution of Cu6Sn5 in a solder joint containing a single β-Sn grain with representative orientation was revealed. It is found that the growth of primary Cu6Sn5 rods and the formations of Cu6Sn5 rods/particles within the matrix and on the anode/cathode interfaces are all heavily influenced by local Cu concentrations and Cu diffusion fluxes in β-Sn, which are controlled by the β-Sn orientation and geometry of the solder joint. The unobvious growth of some Cu6Sn5 is also attributed to the high angles between [0001]Cu6Sn5 and [001]β-Sn (>45°). The orientation relationship between β-Sn and Cu6Sn5 also contributes to the growth direction of the newly formed Cu6Sn5 rod. This study provides insight into the mechanisms of EM-induced microstructure evolutions in ball-grid-array solder joints.

КЛИНИЧЕСКИЙ СЛУЧАЙ АКРОМЕГАЛИИ У ПАЦИЕНТКИ С РЕВМАТОИДНЫМ АРТРИТОМ

Abstract. Introduction. Acromegaly prevalence is 4.6 cases per 1 million person-years, and its rate is 116.9 new cases per 1 million person-years. At the same time, acromegaly manifestations can be insidious, and despite advances in this area, there are significant delays in the diagnosis of the disease, thereby worsening the prognosis for patients. Aim. To study the clinical course of acromegaly in a female patient with rheumatoid arthritis. Materials and Methods. This article presents a clinical case of a 47-year-old female patient with the proven diagnoses of rheumatoid arthritis and acromegaly. Results and Discussion. Essentially, pathological process in rheumatoid arthritis is systemic autoimmune inflammation that most intensively affects the synovial membrane of joints with maximum intensity. Acromegaly-related arthropathy is a non-inflammatory disease, in which hypertrophy and hyperplasia of cartilage lead to the joint geometry perturbations and metabolic disorders in chondrocytes and, eventually, to degenerative changes. This clinical case is interesting, given the coexistence of two severe diagnoses that have a similar clinical picture of musculoskeletal damages. Conclusions. Related to the findings from this clinical case, attention should be paid to the importance of timely diagnosing acromegaly, considering potential influence of concomitant pathology on the clinical course of the disease

Static behaviour of the selected carpentry joints in the flexural elements

The paper presents the static behaviour of the selected carpentry joints in the bending wooden elements. Experimental research on beams with the carpentry joints created according to the geometry of the historical joints was conducted. It was confirmed that some of the longitudinal joints applied in the historical structures, with the proper strengthening elements, could transfer some bending moments, which is important in the flexural elements. The load-carrying capacity of the joined beams was determined and compared to the load-carrying capacity of the reference continuous beams, which was from 30 % to 40 %, depending on the joint geometry. Moreover, the stiffness level of the joined beams was determined and compared to the stiffness of the reference continuous beams, which was from 35 % to over 60 %, also depending on the joint geometry. The force-deflection plots for the tested beams were presented. The failure patterns for the joints were described and based on them the areas of stress concentrations in the joints were identified. The joints worked asymmetrically and their failure occurred as a result of gradual loosening and then cracking – interruption of the continuity of the wood fibres. The role of the applied fasteners, which to some extent protect against loosening of the joints, and partially transfer the applied load, was confirmed. The obtained results were compared to the results from the literature regarding similar connections. Research results can be helpful in designing and performing repair and conservation work in historic wooden structures with carpentry joints, in the event of, for example, the need to recreate a historical joint or replenish part of the substance in an existing joint.

An Equivalent Structural Stress-Based Frequency-Domain Fatigue Assessment Approach for Welded Structures under Random Loading

Welded structures under random loadings are usually susceptible to fatigue-induced failures that lead to significant economic and safety effects. However, accurately predicting these structures’ fatigue damage and life in the frequency domain remains challenging due to the limitations associated with using traditional weld stress extrapolation methods, such as nominal, hotspot, and notch stress methods. These methods struggle with precisely defining and characterizing the stresses at the weld toe and root as they vary depending on factors like weld stress concentration effects, joint geometry, and loading modes. This research introduces an Equilibrium Equivalent Structural Stress (EESS)-based frequency-domain fatigue analysis approach for welded structures subjected to random loading. The proposed method utilizes the EESS formulations, which are based on the decomposition and characterization of weld toe stresses with a single stress parameter, together with incorporating structural dynamic properties’ effects on the stresses acting on the weld joints and the corresponding accumulated fatigue damage of the structure. The numerical demonstration and validation of the proposed method have been performed using a welded Rectangular Hollow Section (RHS) T-joint structure subjected to stationary random fatigue loading. The proposed method’s fatigue damage and life results are compared with the fatigue test data and the equivalent hotspot stress extrapolation-based technique results.

Robust optimization for geometrical design of 2D sequential interlocking assemblies

In the realm of sustainable construction within a circular economy, the study of demountable buildings garners significant interest. Achieving the full potential of reusing materials from disassembled structures demands innovative assembly methods surpassing conventional fasteners like nails. Although traditional joinery has addressed this challenge to some extent, it faces design limitations. Modern digital fabrication technologies, such as CNC milling and additive manufacturing, have expanded the horizons for manufacturable assemblies. This paper builds upon prior research to introduce a flexible method for crafting 2D assemblies adaptable to various geometric assumptions. It offers two contributions. Firstly, it provides a versatile numerical model for analyzing the mechanical properties of diverse designs, uncovering novel assemblies with superior mechanical performance compared to traditional configurations. Secondly, it presents an optimization approach enabling precise control over assembly and disassembly of imperfect parts by optimizing joint geometry. By integrating advanced fabrication techniques, adaptable design methods, and mechanical analysis, this research paves the way for the development of sustainable and mechanically efficient demountable buildings.

Fracture energy and cohesive law analysis of adhesives using a recently developed SCB joint: The influence of joint geometry and mode mixity

In a prior study, the current authors proposed the utilization of semi-circular bend (SCB) specimens for analyzing the fracture energy of adhesive materials. However, similar to standard fracture test specimens, the geometry and size of the joint can impact the measured fracture energy when using SCB samples. Therefore, the objective of this research is to investigate the influence of adhesive layer thickness, substrate thickness, and disk radius of SCB specimens on cohesive law parameters and fracture energy of the adhesive. The study examines the fracture energy under different loading conditions, including pure mode I, pure mode II, and two mixed-mode conditions. By employing an inverse data reduction method, the cohesive law parameters of the tested adhesive are determined for various joint geometries. The results demonstrate that the disk radius does not affect the cohesive law of the joint. Furthermore, it is observed that bondline thicknesses of 0.2 mm and 0.4 mm lead to similar cohesive laws, whereas an adhesive thickness of 1 mm results in lower initial stiffness but higher fracture energy and damage initiation traction. Moreover, the study reveals that an increase in substrate thickness reduces the final fracture separation, indicating a more brittle fracture behavior. This can be attributed to a smaller fracture process zone caused by the plane strain load distribution in the adhesive layer.

Effects of ceramic fillers on failure loads and failure mechanisms of laminated composites with two-parallel pin-loaded holes

In this study, the failure load values and failure mechanisms of ceramic materials filled E-glass/epoxy laminated composite plates that have two-parallel circular holes, subjected to tension forces by two-parallel rigid pins, are investigated experimentally. The composite plates used in the pin tests were produced by using three different ceramic fillers, which are Silicon Carbide (SiC), Boron Carbide (B4C), and Aluminum Oxide (Al2O3). The weight fractions of ceramic fillers in each composite plate are 5%, 10%, and 15%. For evaluating the influence of joint geometry on failure loads and failure mechanisms, the edge distance-to-hole diameter ratio, different pin-hole diameters, and the ratio of the distance between the side edge of the sample and the center of pin-hole to the hole diameter were considered as geometric parameters. The results from the experimental tests revealed that adding ceramic fillers to the composites up to a certain ratio leads to a remarkable increment in the failure load values of the composites compared to the neat (0 wt.%) composites for all weight fractions. Further, the ultimate failure load values were obtained for composite plates filled with Al2O3 ceramics in 10% weight fractions.

The Effect of Joint Thickness on Intermetallic Growth in the In52Sn48(Liquid)/Cu(Solid) Diffusion Couple

Intermetallic growth can simultaneously enable low-resistance electrical pathways and determine the lifetime of a solder joint. Motivating this work is a demountable linear bilateral solder joint application, enabled via a vacuum pressure impregnation process. The effect of the initial solder joint thickness δj=25-125\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\delta _j = 25 - 125$$\\end{document}μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mu $$\\end{document}m on intermetallic growth in this configuration is investigated for the In52Sn48\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{In}_{52}\ ext{Sn}_{48}$$\\end{document}(liquid)/Cu(solid) diffusion couple for temperatures T = 393, 413 and 433 K, in the range just above the In52Sn48\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{In}_{52}\ ext{Sn}_{48}$$\\end{document} melting temperature of 391 K. It was found that beyond a critical time ∼1-15\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sim 1-15$$\\end{document} min into the kinetic reaction, thicker solder joints had more intermetallic growth. There are two intermetallic phases identified in this temperature range: Cu6(In,Sn)5\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{Cu}_{6}\ ext{(In,Sn)}{_5}$$\\end{document} closer to the Cu substrate, and Cu(In,Sn)2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{Cu(In,Sn)}_{2}$$\\end{document} closer to the solder bulk. The intermetallic growth fits give temporal growth exponents between n=0.25-0.29\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$n = 0.25 - 0.29$$\\end{document}, indicating that grain boundary diffusion rather than volume diffusion is the predominant growth mechanism. Growth in thicker joints is associated with higher temporal growth exponents; this is attributed to suppressed grain coarsening, as there is Cu dissolution from the intermetallic into the solder bulk in the early stages of the reaction, in more highly unsaturated environments. In addition, there is on average a decrease in the intermetallic phase activation energy with increasing joint thickness. In combination with the literature, the results suggest the linear bilateral joint geometry has a growth constraining effect, and the liquid solder phase state strongly affects the morphology and coarsening of grains, leading to the intermetallic growth trends observed.

Three-dimensional finite element simulation and reconstruction of jointed rock models using CT scanning and photogrammetry

The geometry of joints has a significant influence on the mechanical properties of rocks. To simplify the curved joint shapes in rocks, the joint shape is usually treated as straight lines or planes in most laboratory experiments and numerical simulations. In this study, the computerized tomography (CT) scanning and photogrammetry were employed to obtain the internal and surface joint structures of a limestone sample, respectively. To describe the joint geometry, the edge detection algorithms and a three-dimensional (3D) matrix mapping method were applied to reconstruct CT-based and photogrammetry-based jointed rock models. For comparison tests, the numerical uniaxial compression tests were conducted on an intact rock sample and a sample with a joint simplified to a plane using the parallel computing method. The results indicate that the mechanical characteristics and failure process of jointed rocks are significantly affected by the geometry of joints. The presence of joints reduces the uniaxial compressive strength (UCS), elastic modulus, and released acoustic emission (AE) energy of rocks by 37%–67%, 21%–24%, and 52%–90%, respectively. Compared to the simplified joint sample, the proposed photogrammetry-based numerical model makes the most of the limited geometry information of joints. The UCS, accumulative released AE energy, and elastic modulus of the photogrammetry-based sample were found to be very close to those of the CT-based sample. The UCS value of the simplified joint sample (i.e. 38.5 MPa) is much lower than that of the CT-based sample (i.e. 72.3 MPa). Additionally, the accumulative released AE energy observed in the simplified joint sample is 3.899 times lower than that observed in the CT-based sample. CT scanning provides a reliable means to visualize the joints in rocks, which can be used to verify the reliability of photogrammetry techniques. The application of the photogrammetry-based sample enables detailed analysis for estimating the mechanical properties of jointed rocks.

Mode I fracture of thick adhesively bonded GFRP composite joints for wind turbine rotor blades

This article investigates the effects of voids, joint geometry, and test conditions on the quasi-static Mode I fracture performance of thick adhesive Double Cantilever Beam (DCB) joints such as those prevailing in wind industry and shipbuilding. The specimens were made by glass fiber reinforced epoxy adherend and SikaPower®-830 epoxy adhesive in the cm thickness range. Side-grooved shape guided the crack propagation direction and assisted stable propagation, while lower cross-head displacement rates reduced the occurrence of unstable crack propagation and prevented crack deflection. Porosities, which are inevitable due to the high viscosity of the adhesive, led to unstable propagation and promoted crack path deviations. They could also decrease the apparent fracture energy release rate (SERR) since the crack surface is reduced. In conclusion, grooved DCB joints with low void content tested at low displacement rates showed stable crack propagation without significant crack path deviation. This method enables comparison with future adhesive formulations and the refinement of full-scale blade models.

Back-Analysis of Structurally Controlled Failure in an Open-Pit Mine with Machine Learning Tools

Over the past decades, numerical modelling has become a powerful tool for rock mechanics applications. However, the accurate estimation of rock mass input parameters remains a significant challenge. Machine learning (ML) tools have recently been integrated to enhance and accelerate numerical modelling processes. In this paper, we demonstrate the novel use of ML tools for calibrating a state-of-the-art three-dimensional (3D) finite-element (FE) model of a kinematic structurally controlled failure event in an open-pit mine. The failure event involves the detachment of a large wedge, thus allowing for the accurate identification of the geometry of the rock joints. FE models are automatically generated according to estimated ranges of joint input parameters. Subsequently, ML tools are used to analyze the synthetic data and calibrate the strength parameters of the rock joints. Our findings reveal that a relatively small number of models are needed for this purpose, rendering ML a highly useful tool even for computationally demanding FE models.