Calculation Of Critical Loads Research Articles

Numerical and Analytical Study of the Cyclic Behavior of ADAS Damper and the Effect of Axial Force on its Behavior

ABSTRACT The objective of this research was to study ADAS dampers and develop equations to calculate their seismic parameters. A model was used to analyze the dampers with various variables. The study proposed equations for stiffness, energy dissipation, and strength of the dampers. It also identified the variables with the most and least impact on the results. The effect of axial force on damper performance was investigated, including the calculation of critical load and examining its influence on stiffness, strength, and ductility. Reducing the opening area and height and increasing the width of the damper increased energy dissipation and effective stiffness.

Symmetrical wrinkling of compressed composite SSCF facings of a rectangular sandwich plate

Results of the study of symmetrical facing wrinkling of compressed rectangular composite sandwich plates with orthotropic faces and core are presented in the paper. Two parallel edges of the plate facings are simply supported, one edge is clamped, and another edge is free (SSCF). The wrinkling problem is solved using the Ritz method in which the total energy functional of plate faces and core is obtained based on the original model, considering nonlinear variation of the transverse displacement of the core material from the value of facing’s deflection to zero. Application of the Ritz method yields formulas for the calculation of critical compressive load. The critical load is found using a minimization with respect to the parameter of the wrinkling waves evolution and the parameter characterizing the rate of fading of the transverse displacement. Based on the derived formulas, the effects of facing and core thicknesses, and modulus elasticity of core material on the critical wrinkling load are studied. The results of calculations are verified using a finite element analysis. It is shown that the value of critical load calculated based on the proposed model is more accurate compared to that calculated using the Winkler-Pasternak model, particularly for the sandwich plates with thin faces and thick core.

Dynamic response of a sea-crossing cable-stayed suspension bridge under simultaneous wind and wave loadings induced by a landfall typhoon

Sea-crossing bridges with long spans are sensitive to wind and wave environments. The estimation of the dynamic response under simultaneous wind and wave loadings is hence important for the safety of bridges, especially during the landfall of typhoons when extreme wind and wave actions usually occur. In this paper, a framework combining the simulation of typhoon wind and wave fields, calculation of aerodynamic and hydrodynamic loadings, and structural analysis was adopted to assess the dynamic response of a sea-crossing bridge. A cable-stayed suspension bridge located in the typhoon-affected area was taken as an example. The inhomogeneity of wave loading, the time-varying dynamic response of bridges during the landfall process, and the effect of critical wave load calculation on extreme response were presented and discussed. Results demonstrated that wave loadings at different pies show strong inhomogeneity during the landfall process. The typhoon-induced simultaneous wind and wave loadings could affect not only the amplitude of the power spectrum density but also the number of dominant modes of the response. In addition, the error brought by excluding the wave inhomogeneity and the time lag of wind and wave in estimating the extreme response was acceptable when the maximum wind loadings were adopted.

Pure/combined buckling mode calculation of thin-walled members constraining general shell FE models

This paper proposes a technique for decomposing the buckling solution of thin-walled members into pure deformation modes (global, distortional, local, or other), aiming at providing an insight into the buckling behavior of these members. The calculation of critical loads associated with a specific or combined deformation mode is performed constraining general finite element models. A general constraining procedure is presented, in which the critical load of any mode, combining different section deformation modes and different harmonic shape functions in the longitudinal direction, can be determined. Cases where all possible harmonic terms may be automatically considered are also described. Cross-section deformation modes are defined in the context of the constrained finite strip method (base vectors), and the proposed constraining procedure is implemented by means of relationships between degrees of freedom of the finite element mesh in commercial software. Calculation of combined buckling modes inherently makes it possible to quantify the participation of the considered modes, including along specific longitudinal segments of the member. Results from the analysis of a lipped channel member are presented to demonstrate the concepts and, later, the analysis of a member with a more complex cross-section and intermediate boundary conditions along length is detailed. A discussion on the base vectors chosen for the constraining method is presented. Finally, the potential of the proposed method is discussed.

Stability Calculation of the Plane Steel Frame Structures Using Tangent Modulus Theory

This paper considers the phenomenon of the instability of steel plane frame structures in the elastic–plastic domain. The numerical analysis uses finite element method, where the corresponding stiffness matrices are based upon the trigonometric and hyperbolic interpolation functions of normal forces. The tangent modulus concept is applied when buckling occurs in the plastic range. Thus, the stiffness matrices for nonlinear material behavior are also derived. The procedure for determining effective length factors of compressed columns, which implies a global stability analysis of entire frames, is established too. It means that the proposed approach is based on the assumption that the collapse of the structure occurs when the most loaded columns reach their stability limit. So, the presented procedure enables the calculation of the real critical load of plane frame structures in the elastic–plastic domain and determines the corresponding effective length factors.

Calculation of Linear Buckling Load for Frames Modeled with One-Finite-Element Beams and Columns

Critical linear buckling load calculation is one of the possible ways to check structural stability. Structural analysis programs usually model beams and columns with just one element, but this is not enough to obtain an accurate value of the critical buckling load when the buckling mode is associated with an effective length that is less than twice the element length. This paper presents a method for the accurate calculation of the buckling load of frames modeled with only one finite element per structural element. For this purpose, a local correction is applied to some elements a few times until convergence is achieved. The validity of the presented method is confirmed by several examples ranging from simple canonical cases to large structures.

Theoretical calculation method for critical buckling load of locally stiffened U-shaped steel sheet pile using the dynamic coordination coefficient method

In order to solve the problem that U-shaped steel sheet piles (USSSPs) are prone to buckling when inserted, we propose a local stiffened U-shaped steel sheet pile destabilization critical load calculation method, namely ‘dynamic alignment coefficient method’, and analyze the influence of stiffening area, stiffening position and number of stiffening plates on the stiffening effect.The study shows that when the total stiffening area is certain, there is a scheme of stiffening plate arrangement to maximize the critical load value of USSSPs with determined length,and reveals the law of local instability caused by the small width of single stiffening plate when the number of blocks is too large. The critical load value of the member can be increased by 13.55% with the variation of the single stiffener plate arrangement position for 10 m long USSSPs, and the optimized theoretical scheme of stiffener plate arrangement for 10 m and 30 m long USSSPs with different total stiffener area is obtained.

Investigation of the overall stability of welded I-beams with a cross-corrugated wall of the Zeman range

Introduction. Welded I-beams with a transversely corrugated wall when loaded in the wall plane are calculated for overall stability in accordance with paragraph 20.6.3.11 of СП 294.1325800.2017, change 2 from 06/15/2021. Here, a separate centrally compressed girder belt is calculated for overall longitudinal stability from the plane of the beam wall as an element pivotally supported at the ends. This does not take into account the joint work of the compressed belt with the wall, supporting ribs, stretched belt.The authors set a goal to show by calculation using the examples of six beams that if, in comparison with the calculation according to СП 294.1325800.2017, the joint work of the compressed belt with the wall, support ribs, stretched belt is taken into account, then the calculated critical load of the total loss of stability of the corrugator will be greater. And this increase is the more significant, the lower the height of the corrugator. At the same time, the authors limited themselves to considering beams with a ratio of sizes and critical loads that ensure the operation of steel in the elastic stage with loss of overall stability.Materials and methods. The general stability of split beams with a transversely corrugated wall was studied by calculation in three ways: according to СП 294.1325800.2017, in the LIRA-CAD PC by modelling beams with shell elements, including belts, walls and support ribs, and according to CП 16.13330.2017, considering a welded I-beam with a flat wall equivalent to the criterion of general stability.The results of the study. The data of calculation of critical loads of the first form of loss of general stability of six split beams of the Zeman range with height are given 333, 500, 750, 1000, 1250, 1500 with a span of 6.0 m in three proposed ways with loading of the upper belt with a uniformly distributed load in the wall plane without loosening the compressed belt in the span and loosening the support sections from the wall plane and from rotation relative to the axis of the beams.Discussion and conclusions. For beams with a wall height of 333 mm, taking into account the joint work of the compressed belt with the wall, stretched belt, support ribs showed an increase in critical load in comparison with the calculation according to СП 294.1325800.2017 by 24%. With an increase in the height of the beams to 900-1000 mm, the difference in the values of critical loads calculated taking into account the joint work of the beam elements and according to СП 294.1325800.2017 non-linearly decreases to 3%. And for corrugated rollers with a height of 1000-1500 mm, this difference is less than 3%, which shows that it is possible to perform calculations of beams with a transversely corrugated wall of the Zeman range with heights of 1000-1500 mm for overall stability with sufficient accuracy for engineering calculations according to СП 294.1325800.2017.

Determination of Critical Loads for Eutrophying and Acidifying Air Pollutant Inputs for the Protection of Near-Natural Ecosystems in Germany

Under the Convention on Long-Range Transboundary Air Pollution (CLRTAP) of the UN Economic Commission for Europe, UNECE, to which Germany acceded in 1982, the harmful effects of air pollutants on the environment are to be steadily reduced and ultimately limited to a level that is compatible with nature. The ICP Modelling & Mapping (ICP M&M) under the Working Group on Effects (WGE) of CLRTAP maps critical loads for the entire Convention area and calculates the exceedance risks and associated risks to vegetation and biodiversity. A current data request was made in November 2015 with the aim of submitting new or updated ecosystem-specific critical loads for protection against acidification and eutrophication. For this task, critical loads were determined by the authors for one third of the territory of Germany using the simple mass balance (SMB) method according to the ICP Mapping Manual. The permissible eutrophying nitrogen input into the ecosystem CLnut(N), as well as the acidifying sulphur input CLmaxS, can be described as the setting of the equilibrium between substance inputs and outputs, provided that specific critical limits are met. The BERN database—created by the authors—serves as the basis for modelling vegetation-specific critical limits as a complement to the SMB model. The BERN database contains near-natural plant communities with clearly definable site constancy. The 25,600 German and a further 24,600 European vegetation records dating back to before 1960 were evaluated to determine the good ecological status of the plant communities. The results of the critical load calculation show that about half of the receptor areas have critical loads for eutrophying nitrogen below 10 kg ha−1 a−1 and critical loads for acidifying sulphur were below 1500 eq ha−1 a−1. It could be demonstrated that the BERN–SMB-modelled critical loads for eutrophying nitrogen inputs show lower values on average throughout Germany than those calculated using only the previous critical limits according to the ICP Mapping Manual. These values are closer to the empirical critical loads than the critical loads without BERN data. For the goal of the German National Biodiversity Strategy by 2007 and 2020 to define ecosystem-related impact thresholds for pollutants that describe the effects on biodiversity, the BERN/SMB critical loads for the protection of ecosystems provide a precautionary scientific basis.

ON THE QUESTION OF THE STABILITY OF SHELLS, PLATES AND RODS

Strict, often conflicting requirements are imposed on modern engineering structures. On the one hand, they must be light, and on the other hand, their load-bearing capacity must be high. The exhaustion of the bearing capacity often occurs due to the loss of stability of structural elements: shells, plates and rods. There are no reliable formulas for determining the critical loads of plates and, moreover, shells. The purpose of this paper is to find such formulas. A new approach to solving stability problems is used, based on the assumption that at the moment of stability loss, the axial compressive force decreases. Based on this approach, by the energy method using the relations of the general linear theory of thin-walled shells, formulas were obtained for calculating the axial critical forces of cylindrical shells with hinged and rigidly embedded ends, rectangular plates and rods. The results of critical load calculations using these formulas are in good agreement with the experimental data. The results of an experimental study of the stability of cylindrical shells reinforced with stringers under axial compression are presented. Conclusions are drawn and recommendations are given on the use of the proposed approach for further study of the stability of thin-walled structures.

Calculation of Critical Load of Axially Functionally Graded and Variable Cross-Section Timoshenko Beams by Using Interpolating Matrix Method

In this paper, the interpolation matrix method (IMM) is proposed to solve the buckling critical load of axially functionally graded (FG) Timoshenko beams. Based on Timoshenko beam theory, a set of governing equations coupled by the deflection function and rotation function of the beam are obtained. Then, the deflection function and rotation function are decoupled and transformed into an eigenvalue problem of a variable coefficient fourth-order ordinary differential equation with unknown deflection function. According to the theory of interpolation matrix method, the eigenvalue problem of the variable coefficient fourth-order ordinary differential equation is transformed into an eigenvalue problem of a set of linear algebraic equations, and the critical buckling load and the corresponding deflection function of the axially functionally graded Timoshenko beam can be calculated by the orthogonal triangular (QR) decomposition method, which is the most effective and widely used method for finding all eigenvalues of a matrix. The numerical results are in good agreement with the existing results, which shows the effectiveness and accuracy of the method.

Assessing the relevance of atmospheric heavy metal deposition with regard to ecosystem integrity and human health in Germany

BackgroundThe critical values for heavy metal fluxes for protecting the human health and ecosystem’s integrity in Germany, especially the Federal Immission Control Act (BImSchG in Gesetz zum Schutz vor schädlichen Umwelteinwirkungen durch Luftverunreinigungen, Geräusche, Erschütterungen und ähnliche Vorgänge (Bundes-Immissionsschutzgesetz-BImSchG), 1974/2020) with its implementing ordinances (especially the 39th BImSchV in Neununddreißigste Verordnung zur Durchführung des Bundes-Immissionsschutzgesetzes Verordnung über Luftqualitätsstandards und Emissionshöchstmengen vom 2. August 2010, zuletzt geändert durch Art. 2 V v. 18.7.2018 I 1222, 2010, 2018), the Federal Soil Protection Ordinance (BBodSchV in Bundes-Bodenschutz- und Altlastenverordnung (BBodSchV) (GBBl. I S. 1554 vom 12. Juli 1999, zuletzt durch Artikel 3 Absatz 4 der Verordnung vom 27. September 2017 (BGBl. I S. 3465) ge-ändert, 1999/2015) and the Technical Instructions on Air Quality Control (Luft in Erste Allgemeine Verwaltungsvorschrift zum Bundes–Immissionsschutzgesetz (Technische Anleitung zur Reinhaltung der Luft – TA Luft), 2002), were analysed, assessed with regard to the possibilities and applicability of the risk assessment, and were prepared for evaluation in comparison to the respective atmospheric deposition modelled with the chemical transport model LOTOS-EUROS. For a comparison of the critical values, the critical loads for cadmium, lead and mercury inputs were updated for Germany on a scale of 1:1 Mio, and critical loads for additional heavy metals (arsenic, copper, zinc, chromium and nickel) were computed, respectively. Due to the methodological differences of their derivation, the critical values of the individual regulations are only conditionally comparable to one another and to the critical loads. Sometimes major differences exist due to different levels of protection, various protective goods and the effect relationship. Only with the critical load calculations, inputs and outputs can be balanced.ResultsFor two unregulated metals (thallium and vanadium) a preliminary rough estimate of the risk of inputs in the receptors was provided as a calculated balance for in- and acceptable outputs. The uncertainty analysis shows, that the highest deviations occurred in the metal contents in plants used to calculate the output through the harvesting of the biomass. The critical load calculation has the highest sensitivity to changes in the pH value. The critical loads for heavy metal fluxes for protecting the human health (CL(M)drink) and ecosystem’s integrity CL(M)eco) for arsenic, nickel, zinc and chromium were not exceeded in Germany for 2009–2011. CL(M)drink and CL(M)eco are exceeded by Hg and Pb inputs, especially in the low rainfall regions of Germany (Brandenburg, lowlands of Saxony-Anhalt, Leipzig Bay, Ruhr valley) with wood vegetation; in addition CL(Cu)eco is exceeded by copper deposition 2010 in the area surrounding Berlin and in the Ruhr valley. The critical loads for cadmium for the protection of drinking water CL(Cd)drink and for the protection of human food from wheat products CL(Cd)food are not exceeded in the German data set due to atmospheric deposition in 2010, but in the worst-case scenario the maximum atmospheric deposition in 2010 could exceeded the lowest CL(Cd)drink and CL(Cd)food.ConclusionsThat assessment of risks was based on deposition from the atmosphere, which represents only a fraction of the inputs compared to the inputs from the use of fertilisers and other sources. This study suggests the conclusive recommendation to methodically deepen and broaden the assessment and evaluation of atmospheric deposition. This is especially true for the spatial validation and specification of exposure for ecosystem types.

Dynamic Stability Critical State of Pin-Ended Arches under Sudden Central Concentrated Load

The dynamic in-plane instability process of extreme point type for pin-ended arches when a central radial load applied suddenly with infinite duration is analyzed with finite element method in this study. The state of arch can be determined by the crown’s vertical displacement varied with time and the critical load can be obtained by repeating trial-calculation. When the arch structure reaches the dynamically stable critical state, the kinetic energy of the structure is very small or even zero. The dynamic critical load of elastic arch calculated with the theoretical analysis method which is based on energy principle is proved accuracy enough by comparing with the finite element calculation results and the percentage of the differences between them are no more than 4.5 %. The maximal elastic strain energy is certain for the elastic-plastic arch in certain geometry under both a sudden load and static load. The maximal elastic strain energy in static calculation can be used in determining the state of the elastic-plastic arch under dynamic sudden loads applied and this method is more accurate which errors won’t exceed 3.5 %. The accuracy of dynamic critical load calculation method for elastic arch is verified by numerical calculation in this study, and based on the characteristic of elastic strain energy in critical state, a method for determining the stability of elastic-plastic arch is presented.

Assessing critical load exceedances and ecosystem impacts of anthropogenic nitrogen and sulphur deposition at unmanaged forested catchments in Europe

Anthropogenic emissions of nitrogen (N) and sulphur (S) compounds and their long-range transport have caused widespread negative impacts on different ecosystems. Critical loads (CLs) are deposition thresholds used to describe the sensitivity of ecosystems to atmospheric deposition. The CL methodology has been a key science-based tool for assessing the environmental consequences of air pollution. We computed CLs for eutrophication and acidification using a European long-term dataset of intensively studied forested ecosystem sites (n = 17) in northern and central Europe. The sites belong to the ICP IM and eLTER networks. The link between the site-specific calculations and time-series of CL exceedances and measured site data was evaluated using long-term measurements (1990–2017) for bulk deposition, throughfall and runoff water chemistry. Novel techniques for presenting exceedances of CLs and their temporal development were also developed. Concentrations and fluxes of sulphate, total inorganic nitrogen (TIN) and acidity in deposition substantially decreased at the sites. Decreases in S deposition resulted in statistically significant decreased concentrations and fluxes of sulphate in runoff and decreasing trends of TIN in runoff were more common than increasing trends. The temporal developments of the exceedance of the CLs indicated the more effective reductions of S deposition compared to N at the sites. There was a relation between calculated exceedance of the CLs and measured runoff water concentrations and fluxes, and most sites with higher CL exceedances showed larger decreases in both TIN and H+ concentrations and fluxes. Sites with higher cumulative exceedance of eutrophication CLs (averaged over 3 and 30 years) generally showed higher TIN concentrations in runoff. The results provided evidence on the link between CL exceedances and empirical impacts, increasing confidence in the methodology used for the European-scale CL calculations. The results also confirm that emission abatement actions are having their intended effects on CL exceedances and ecosystem impacts.

Mechanism and quantitative evaluation model of slip-induced loosening for bolted joints

PurposeBolted joints are the most common type of mechanical connections, and improving the anti-loosening performance of bolts for the reliable performance of mechanical and building structures is highly significant.Design/methodology/approachBecause of the lack of sufficient theoretical basis for the evaluation and design of anti-loosening bolts, a quantitative evaluation model exhibiting the following two evaluation criteria for anti-loosening bolts is introduced: bolt rotation angular acceleration criterion and critical transverse load criterion. Based on the relationship among bolt tension, transverse load and bolt rotation angular acceleration, a critical transverse load calculation model is put forward, and the mechanism by which the critical transverse load increases with the increase of bolt tension is revealed.FindingsBased on the above model, a new type of anti-loosening bolt is designed, which generates additional bolt tension when the transverse load increases, and then improves the critical transverse load of the bolt. The effectiveness of the new type of anti-loosening bolt is verified by theoretical calculations and experiments.Originality/valueThe proposed model and method set a preliminary theoretical foundation for the evaluation of bolt anti-loosening performance and the design of a new anti-loosening bolt.

Application of the Method of Stationary Perturbation Theory to the Calculation of Critical Loads in the Problem of Longitudinal Bending of the Rod

Application of the Method of Stationary Perturbation Theory to the Calculation of Critical Loads in the Problem of Longitudinal Bending of the Rod

Construction of elastoplastic shallow panels manufactured by stretching from sheet metal

In the article, in a geometrically and physically nonlinear formulation, the problem of the stress-strain state of shallow shells on a rectangular plane under pressure loading is solved. The solving equations of the theory of flexible shallow shells are obtained on the basis of the Henki-Ilyushin deformation theory of plasticity and the equations of the geometrically non-linear theory of shells, which contain quadratic terms with respect to the angles of rotation of the normals to the median surface. The geometrical parameters of the median surface are taken in the initial undeformed state. The equations are written in a form that makes it possible to carry out numerical calculations of problems with allowance for geometric and physical nonlinearities or only with geometric nonlinearity, to take into account unloading, compressibility of the material and secondary plastic deformations. The results of numerical calculations of critical loads, unloading zones and secondary plastic deformations are presented. Recommendations are given on the choice of geometrical parameters when designing shallow shells.

Calculation of Critical Load for Pure Distortional Buckling of Lipped Channel Columns

This paper presents a method that allows calculating the elastic critical stress for the distortional buckling mode, based on the buckling mode classification of typical lipped channel columns. In our case, Cold-Formed Steel Lipped Channel Columns are subjected to compression. Moreover, in order to consolidate the important findings of this work, a comparative study was carried out to assess the reliability of various distortional buckling models that are provided by different design Standards. It was found that the American and Australian approaches, given in the codes of practice, are closer to the Finite Strip Method than to the European method. An analytical solution was proposed for the determination of the distortional buckling stress on the basis of a statistical method; it corresponds to lipped channel sections with a flange width to web width ratio b/h ranging from 0.1 to 1, and a lip width to web width ratio c/h between 0 and 0.5. After comparison with the results given by the finite strip method for pure distortional buckling, it turned out that the proposed approach provides a reasonable prediction for the elastic distortional buckling stress for lipped channel sections subjected to compression. In fact, this method gives better results than the American approach.

Nonlocal strength criteria for the calculation of critical loads in bended structural elements, taking into account the nonlinearity of the material deformation

The destruction of artificial materials (plexiglas, ebonite) in non-uniform stress fields was experimentally investigated. Testing of one batch of samples is carried out using various methods: three-point and clean (four-point) bending of rectangular cross-section beams, Brazilian test (method of splitting a cylinder along a generator). The comparison of the strength characteristics obtained by the Brazilian test with the uniaxial tensile strength, as well as with the tensile strength during bending tests. Experiments on the fracture of beams on a three-point flexural test revealed higher values of ultimate tensile stress than those of a four-point flexural test. The processing of the experimental data obtained by the Brazilian test is carried out using various non-local strength criteria. A sequential analysis of the applicability of the criteria used in the determination of failure loads is carried out. Computer simulation was performed using the finite-element method for the destruction of a cylinder by splitting along a generator, three-point and four-point bending flexural test of a beam in a geometrically nonlinear formulation, taking into account the non-linearity of the material deformation diagram. The problem was solved in the updated Lagrangian formulation taking into account the physical and geometric nonlinearity based on the governing equations of the hypoelastic material. A comparative analysis of the numerical, analytical and experimental results is carried out. A qualitative correspondence was obtained between the experimental data and the results of numerical calculations.

The importance of mineral determinations to PROFILE base cation weathering release rates: a case study

Abstract. Accurate estimates of base cation weathering rates in forest soils are crucial for policy decisions on sustainable biomass harvest levels and for calculations of critical loads of acidity. The PROFILE model is one of the most frequently used methods to quantify weathering rates, where the quantitative mineralogical input has often been calculated by the A2M (“Analysis to Mineralogy”) program based solely on geochemical data. The aim of this study was to investigate how uncertainties in quantitative mineralogy, originating from modeled mineral abundance and assumed stoichiometry, influence PROFILE weathering estimate, by using measured quantitative mineralogy by X-ray powder diffraction (XRPD) as a reference. Weathering rates were determined for two sites, one in northern (Flakaliden) and one in southern (Asa) Sweden. At each site, 3–4 soil profiles were analyzed at 10 cm depth intervals. Normative quantitative mineralogy was calculated from geochemical data and qualitative mineral data with the A2M program using two sets of qualitative mineralogical data inputs to A2M: (1) a site-specific mineralogy based on information about mineral identification and mineral chemical composition as determined directly by XRPD and electron microprobe analysis (EMPA), and (2) regional mineralogy, representing the assumed minerals present and assumed mineral chemical compositions for large geographical areas in Sweden, as per previous published studies. Arithmetic means of the weathering rates determined from A2M inputs (WA2M) were generally in relatively close agreement with those (WXRPD) determined by inputs based on direct XRPD and EMPA measurements. The hypothesis that using site-specific instead of regional mineralogy will improve the confidence in mineral data input to PROFILE was supported for Flakaliden. However, at Asa, site-specific mineralogies reduced the discrepancy for Na between WA2M and WXRPD but produced larger and significant discrepancies for K, Ca and Mg. For Ca and Mg the differences between weathering rates based on different mineralogies could be explained by differences in the content of some specific Ca- and Mg-bearing minerals, in particular amphibole, apatite, pyroxene and illite. Improving the accuracy in the determination of these minerals would reduce weathering uncertainties. High uncertainties in mineralogy, due for example to different A2M assumptions, had surprisingly little effect on the predicted weathering of Na- and K-bearing minerals. This can be explained by the fact that the weathering rate constants for the minerals involved, e.g. K feldspar and micas, are similar in PROFILE. Improving the description of the dissolution rate kinetics of the plagioclase mineral group as well as major K-bearing minerals (K feldspars and micas) should be a priority to help improve future weathering estimates with the PROFILE model.