jsb2505

/* 
A function to calculate alpha as given by Appendix G in SCI P398

INPUTS: m, m2 and e 
RETURNS: value of alpha

Example:
    =GetAlpha(40,45,35)
Returns:
    5.345

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Materials = {"Softwood", "Hardwood", "Glulam", "LVL", "Green_Oak"};

Material_Properties = {
    "strength_class",
    "f_m_y_k",
    "f_v_k",
    "f_c_90_k",
    "E_0_mean",
    "G_mean",
    "E_005",

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Tree_Names = CHOOSECOLS(Tree_Data,1);

/**
Contains a table of trees in the format:

tree_name, tree_type, water_demand, mature_height
*/
Tree_Data = {
    "Elm English", "Broad-leafed", "High", 24;
    "Elm Wheatley", "Broad-leafed", "High", 22;

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Get_C_prob = LAMBDA(return_period, [n], [K],
    LET(
        p, return_period,
        n, IF(ISOMITTED(n), 0.5, n),
        K, IF(ISOMITTED(K), 0.2, K),
        ((1 - K * LN(-LN(1 - 1 / p))) / (1 - K * LN(-LN(0.98)))) ^ n
    )
);

Get_C_alt = LAMBDA(altitude, [reference_height],

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/**Partial factor for action DA1 C1 or C2.
EXPECTED INPUTS: 
Combination = 1 or 2. 
Action = "permanent" or "variable". 
Favourability = "unfavourable" or "favourable".
*/
Get_γ_action = LAMBDA(combination_1_or_2_as_number, action, [favourability],
    LET(
        _favourability, IF(ISOMITTED(favourability), "unfavourable", LOWER(favourability)),
        _action, LOWER(action),

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Get_Shape_Factor = LAMBDA(height_of_unit, width_of_unit,
    LET(
        h, height_of_unit,
        w, width_of_unit,
        widths, {50, 100, 150, 200, 250},
        heights, {40, 50, 65, 100, 150, 200, 250},
        shape_factors, 
            {
                0.80, 0.70,   "",  "",    "";
                0.85, 0.75, 0.70,  "",    "";

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UB_Table = {
    //{"type","name",mass,height,breadth,web_thickness,flange_thickness,root radius}
    "UB", "127 x 76 x 13", 13, 127, 76, 4, 7.6, 7.6;
    "UB", "152 x 89 x 16", 16, 152.4, 88.7, 4.5, 7.7, 7.6;
    "UB", "178 x 102 x 19", 19, 177.8, 101.2, 4.8, 7.9, 7.6;
    "UB", "203 x 102 x 23", 23.1, 203.2, 101.8, 5.4, 9.3, 7.6;
    "UB", "203 x 133 x 25", 25.1, 203.2, 133.2, 5.7, 7.8, 7.6;
    "UB", "203 x 133 x 30", 30, 206.8, 133.9, 6.4, 9.6, 7.6;
    "UB", "254 x 102 x 22", 22, 254, 101.6, 5.7, 6.8, 7.6;
    "UB", "254 x 102 x 25", 25.2, 257.2, 101.9, 6, 8.4, 7.6;

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/** 
Calculates alpha as given by Appendix G in SCI P398.
Note: always omit last optional parameter
*/
Get_Alpha = LAMBDA(m, m_2, e, [alpha_DONT_INPUT],
    LET(
        lambda_1, m / (m + e),
        lambda_2, m_2 / (m + e),
        alpha, IF(ISOMITTED(alpha_DONT_INPUT), 4.45, alpha_DONT_INPUT),
        lambda_1_temp, Get_Lambda_1(alpha, lambda_2),

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Get_Bending_Moment = LAMBDA(permanent_UDL, imposed_UDL, length_mm,
    LET(
        g_k, permanent_UDL,
        q_k, imposed_UDL,
        L, length_mm,
        γ_g, 1.35,
        γ_q, 1.5,
        (γ_g * g_k + γ_q * q_k) * (L / 1000) ^ 2 / 8
    )
);

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/**Poisson's ratio of concrete.
Ref: EC2 §3.1.3(4)
*/
Get_Poissons_Ratio = LAMBDA([isCracked],
    LET(
        _isCracked, IF(ISOMITTED(isCracked), FALSE, isCracked),
        IF(_isCracked,
            0, //for cracked concrete
            0.2 //for uncracked concrete
        )