Osteosarcoma (OS), a primary malignant bone tumor, poses significant challenges in diagnosis and prognosis. It is a painful medical burden, and treating it is still a difficult issue. Osteopontin ...(OPN), a multifunctional extracellular matrix protein, has emerged as a promising biomarker in this context. This systematic review explores the role of OPN as a diagnostic and prognostic marker in OS, highlighting its potential in enhancing early detection, monitoring disease progression, and predicting patient outcomes. Various studies have demonstrated elevated levels of OPN in OS patients, correlating with tumor aggressiveness, metastatic potential, and poor prognosis. In addition, OPN's involvement in tumor microenvironment regulation and metastatic processes underscores its clinical relevance as a biomarker. For this systematic review, comprehensive literature searches were conducted in the PubMed databases for research published between the database's establishment and November 11, 2022. Out of the nine studies that were available for analysis, a higher level of OPN in primary osteogenic sarcoma patients indicates a poorer prognosis and higher incidence of metastasis. OS has not shown commensurable progress with concerns to treatment approches and survical outcomes. However, the discovery of a biological marker that can predict metastasis and severity will be a groundbreaking development for advancements in OS diagnosis and treatment. Therefore, understanding the intricate interplay between OPN and OS pathogenesis holds promise for improving patient management and developing targeted therapeutic strategies.
As a promising strengthening solution, carbon fiber reinforced polymer (CFRP) sheets have been used to improve the structural response of concrete-filled steel tubes (CFSTs) in service loads, owing ...to the durability and high strength-to-weight ratio provided by CFRP. Despite the wealth of knowledge available in the literature on how CFRP sheets contribute to strengthening CFSTs under static loads, there is a research gap regarding how the strengthened structural components respond to lateral impact loads, due to vehicle and vessel collision, as well as wind and water-borne debris impact. This was the motivation of the current study to establish a computational framework supported by experimental tests to evaluate the performance of CFST beams with and without CFRP under a set of impact scenarios. For this purpose, a range of influential aspects related to CFRP, concrete, and steel, as well as impact energy, are investigated. Such a holistic assessment provides unique information to answer fundamental and practical questions regarding the use of CFRP for strengthening of CFST beams against impact loads. To further assist with the proper configuration of CFRP-strengthened CFST beams, a section analysis method is developed and validated as the outcome of this study.
•This study evaluates four concrete constitutive models for low velocity impact simulations.•The constitutive models are first examined under various stress paths at the material level.•Post-peak ...softening, shear dilation, and confinement effects are investigated.•Both reinforced concrete and concrete-filled steel tube beams are evaluated at the structure level.•A detailed insight for the selection of material models and their parameters is provided.
Concrete structures are commonly exposed to low velocity impact loads originating from windborne/waterborne debris, vehicle/vessel collision, and rock fall. For the performance assessment of concrete structures under such loads, several constitutive models have been developed to date. To compare the accuracy of the available models for practical applications, the current study evaluates four constitutive models, i.e., continuous surface cap model (CSCM), elasto-plastic damage cap (EPDC) model, Karagozian and Case concrete (KCC) model, and Winfrith concrete model. For this purpose, the constitutive models are first examined at the material level through single element simulations under basic stress paths, such as uniaxial compression and tension, as well as triaxial compression. A range of measures, such as post-peak softening, shear dilation, and confinement effect, are extracted and compared. The investigation is then extended to understand how the concrete constitutive models perform at the structure level. This is achieved by replicating drop hammer tests on reinforced concrete (RC) and concrete filled steel tube (CFST) beams. Investigation of these two structural categories provides a unique opportunity to further evaluate the accuracy of the concrete constitutive models in interaction with the most common reinforcement details. To achieve this goal, the impact responses of RC and CFST beams are compared with full-scale experimental test data. Upon understanding the capabilities of each constitutive model in predicting the structural behavior and damage, the most important modeling parameters are examined. The outcome of this study facilitates the selection and use of concrete constitutive models for the design and assessment of concrete structures subjected to various low velocity impact loads.
•Simulations are performed on different roof sections subjected to single and multiple hails of different size.•Roof panels with ribs are found to experience plastic deformations under hail diameters ...greater than 3 in.•The extent of damage increases by up to 20% in subsequent impacts by the hailstones of the same size.•The roof panel impacted by a large-size hail becomes more vulnerable to subsequent hailstones of even a smaller size.
In the event of a hailstorm, several stakeholders, such as home and business owners, as well as insurance companies, are in immediate need to make a decision on repair or replacement of roofs based on their extent of damage. The body of knowledge on the structural response of roofs to hail impact is, however, limited, and as a result, the current roof design and assessment criteria suffer from the absence of a fundamental understanding of the extent of damage under region-specific hail hazards. To address this gap, the current study investigates the hail impact on metal roof panels that are commonly used in residential and commercial buildings. For this purpose, a set of finite-element (FE) impact simulations are conducted. The FE models of the hail developed for this study are first validated with the experimental test data. Hail impact simulations are then performed to assess the vulnerability of critical roof sections subjected to a range of hail diameters. For performance assessment, several measures, including visual damage, as well as displacements, strains, and stresses, are employed. The investigations are then extended to study a chain of hail impacts, which replicate the hailstorm events experienced by roofs in reality. In the first hail impact, the metal roof panels are found to undergo plastic deformations for hail diameters greater than 76.2 mm (3.0 in.). This increases the extent of damage to metal roof panels subjected to subsequent hailstones of the same size by up to 20%. The outcome of this study is expected to provide building, construction, and insurance industries with a fundamental insight necessary for condition assessment purposes. This is deemed a critical input to prevent the failure of metal roofs under hail impact.
Structural insulated panels (SIPs), which consist of a composite of an insulating polymer foam sandwiched between two layers of structural skins, are widely used in residential and commercial ...buildings. Such panels, in the regions prone to hurricanes and tornadoes, are often exposed to the risk of windborne debris impact. Despite the consequences associated with damage to SIPs, the studies on their perforation resistance and design variables have been rather limited. To address this gap, the current study develops a computational framework to assess the vulnerability of the SIPs of various configurations subjected to a range of windborne debris impact scenarios. For this purpose, impact simulations are conducted to quantify the response and evaluate the extent of damage to the SIPs. The study is further extended to evaluate the effect of various structural details and material properties on the perforation resistance of the SIPs. Based on the simulation results, a set of vulnerability curves are developed to capture the risk of failure of the SIPs under the windborne debris hazard. This is expected to improve the design of this important category of wall panels, especially to ensure their safety and performance during severe windstorms.
The design and performance of double-layered structural insulated panels (DL-SIPs) are investigated in this study with a focus on how they resist the windborne debris hazard. Such composite panels ...are commonly used in building envelopes to provide insulation and energy-saving advantages. However, if not designed properly, they can be at the risk of failure due to windborne debris impact, especially in high wind regions. This critical aspect motivated the current study to establish an experimentally-supported computational platform to assess the DL-SIPs, in terms of their key response measures, such as energy absorption, maximum displacement, and projectile penetration. A global sensitivity analysis is then conducted to systematically evaluate the effects of various design variables considered for metal sheets and foam cores on the impact response characteristics of the DL-SIPs. This study is further extended to perform a multi-objective design optimization for the DL-SIPs using two surrogate models (i.e., radial basis function network and kriging model). From the optimization results, the trade-offs between the design details and the impact resistance measures are determined. This leads to a set of configurations recommended for the DL-SIPs to properly resist windborne debris impact, while avoiding an overdesign.
From reconnaissance surveys, plate-type objects, such as roof shingles and tiles, are known to be among the most common types of debris objects. Therefore, a reliable prediction of their flight ...trajectories is instrumental for evaluating the vulnerability of building envelopes, especially in the regions with severe windstorms. Despite the development of several quasi-steady models for this purpose, the current literature lacks high-fidelity models to predict the flight pattern and impact velocity of the windborne debris objects separated from the ground and/or buildings. To address this gap, a coupled computational fluid dynamics and rigid body dynamics simulation framework was developed in the current study to capture the flight trajectories of plate-type debris objects in atmospheric boundary layer winds. Upon establishing a fundamental understanding of main flight characteristics, this study was extended to investigate the effects of initial pitch and yaw angles, plate characteristics, mean wind velocity, and release height on the flight of plate-type debris. In addition, a set of models were developed to predict debris travel distance, as well as linear and angular velocities associated with it. This can be directly employed to assess the impact-induced loading demand that building envelopes are expected to resist due to windborne plate-type debris.
•Flight trajectories of plate-type debris objects were systematically characterized.•A coupled CFD-RBD simulation framework was developed, tested, and validated.•Both uniform and atmospheric boundary layer winds were considered and compared.•Main flight characteristics were determined based on various influential factors.•Predictive models were developed for debris travel distance and impact velocity.
•A novel damage ratio index (DRI) introduced to define damage due to impact loads.•The pier diameter governs the overall failure mode of the pier.•The transverse reinforcement ratio controls the ...amount of localized damage.•The kinetic energy of the impacting vehicle governs the magnitude of internal forces.•Proposed performance-based approach allows for choosing a target performance level.
This paper introduces a novel damage ratio index (DRI) that can be used to define the expected damage due to impact scenarios of vehicles striking bridge piers. The DRI is based on the structural characteristics of the bridge and the kinetic energy of the colliding vehicle. A performance-based approach allows the designer or bridge owner to choose a target performance level based on different parameters, such as the criticality of the bridge to the transportation network or economic constraints. Detailed finite element models of the bridge piers were generated, validated, and verified against a series of available experimental and numerical results from previous research. A detailed review of the effects of different design parameters, including the pier diameter and transverse reinforcement ratio, were considered in the response of the bridge piers to collisions. For this purpose, the internal shear forces, bending moments, and displacements under different collision scenarios were studied. The review showed that the pier diameter governs the overall failure mode, the transverse reinforcement ratio controls the amount of localized damage experienced by the pier, and the kinetic energy of the impacting vehicle governs the magnitude of internal forces generated within the pier. This proposed performance-based design approach is based on the novel DRI, which enables straightforward designs of circular reinforced concrete bridge piers for a vehicle collision event without the use of extensive finite element modeling.
A number of studies have been performed to understand the lateral load carrying capacity of wood frame shear walls. The existing studies, however, have been primarily focused on the intact shear ...walls, disregarding the possibility of capacity loss due to prior extreme loading events. During windstorms, in particular, windborne debris is the leading cause of damage and destruction. While the impact force induced by windborne debris can directly damage a shear wall, the consequences can become disastrous, as the prior damage adversely affects the in-plane lateral load carrying capacity of the shear wall. This critical aspect motivated the current study to investigate the impact and post-impact performance of wood frame shear walls. For this purpose, a high-fidelity computational framework capable of characterizing both types of damage is developed. Further to providing an in-depth understanding of the process of damage formation and propagatin, this study examines how a range of impact scenarios and wall design factors influence the extent of damage that the wood frame shear walls experience in a windstorm. The outcome of this study is then employed to introduce a capacity loss index for the multi-hazard design and assessment of wood frame (and other similar) shear walls in the regions prone to severe windstorms.
•The structural response of wood frame shear walls subjected to wind load and windborne debris impact was investigated.•Impact location, angle of attack, nail spacing, and moisture content were examined as the most critical factors.•With debris impact to sheathing panels, a punching shear failure was observed under impact velocities as low as 10.0 m/s.•The studs tolerated impact velocities above 25.0 m/s, owing to their deformations prior to detachment from framing members.•Up to a third of lateral capacity was lost in the shear walls damaged with debris impact velocities greater than 15.0 m/s.
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